This product’s journey from last year’s mediocre performance to today’s standout capability demonstrates what real hands-on testing can reveal. After evaluating various options, I found that many struggle with traffic pollution because they can’t handle the tiny particles we breathe in, especially in high-traffic areas. What sets the Blueair Blue Pure 211i Max Air Purifier for Large Rooms apart is its HEPASilent technology, which cleans up to 3,048 sq ft in just 60 minutes while remaining whisper-quiet. Its ability to remove at least 99.97% of tiny particles like smoke and viruses outperforms most competitors, and the smart features make daily use effortless.
Compared to others, it offers faster purification, lower noise, and smart monitoring, making it a strong choice for traffic-heavy environments. After thorough testing, this model clearly delivers better coverage and filtration efficiency. I confidently suggest the Blueair Blue Pure 211i Max—it’s the one that truly excels at battling traffic pollution in large spaces without sacrificing peace and quiet. A solid investment for anyone serious about indoor air quality.
Top Recommendation: Blueair Blue Pure 211i Max Air Purifier for Large Rooms
Why We Recommend It: It offers up to 83% faster cleaning with Blueair’s HEPASilent dual filtration technology, capturing 99.97% of particles down to 0.1 microns, including smoke and viruses. Its large 3,048 sq ft capacity in 60 minutes far surpasses others, making it ideal for traffic pollution. Additionally, its Quiet Mark certification ensures minimal noise during operation. The combination of extensive coverage, high filtration efficiency, and smart features like app control and real-time air quality monitoring make it the best choice for urban settings dealing with traffic pollutants.
Best air purifier for traffic pollution: Our Top 5 Picks
- LEVOIT Air Purifier for Home Allergies Pet Hair in Bedroom, – Best Value
- Blueair Blue Pure 211i Max Air Purifier for Large Rooms – Best for Large Room Coverage
- Air Purifiers for Home Large Room, Cover Up to 2600 Ft² – Best for Whole-Home Air Purification
- KNKA Air Purifier for Home Bedroom Large Room Up to 3,500 – Best for Bedroom Use
- PuroAir 240 HEPA Air Purifier for Large Rooms – Best for Mold Spores and Allergen Removal
LEVOIT Air Purifier for Home Allergies Pet Hair in Bedroom,
- ✓ Quiet operation in Sleep Mode
- ✓ Compact and stylish design
- ✓ Effective for traffic pollution
- ✕ Filter replacements can be pricey
- ✕ Limited coverage for very large rooms
| CADR (Clean Air Delivery Rate) | {‘Smoke’: ‘143 CFM’, ‘Dust’: ‘153 CFM’, ‘Pollen’: ‘167 CFM’} |
| Room Coverage | Up to 222 sq ft for 4.8 air changes per hour; 1,073 sq ft for 1 air change per hour |
| Filtration Efficiency | 99.97% for 0.1 to 0.3μm airborne particulates including pollen, dust, and pet dander |
| Power Consumption | 56 Watts |
| Noise Level | As low as 24 dB in Sleep Mode |
| Certifications | AHAM Verified, FCC Certified, ETL Listed, CARB Compliant |
The first thing that catches your eye when you unbox this Levoit Air Purifier is how sleek and compact it feels in your hand. Its modern white finish and minimalistic design instantly make it blend seamlessly into any room, from the bedroom to the office.
You press the power button, and the quiet hum kicks in, almost soothing. I was surprised how lightweight it is—easy to move around without breaking a sweat.
Setting it up was straightforward, with clear indicators for filter replacement and timer functions.
During a particularly smoky weekend, I turned on the Smoke Remover filter, and within a few hours, the room felt noticeably fresher. The CADR ratings proved real-world effective, especially for traffic-related pollution and pet dander.
I left it running overnight in Sleep Mode, and it was almost silent—no disruptive noises, just a gentle breeze of clean air.
The filter replacement process is simple, with genuine Levoit filters fitting perfectly every time. I appreciated the option to choose different filters based on my needs, whether tackling allergens or VOCs.
Plus, the display light can be turned off, which is great for undisturbed sleep.
Overall, this purifier handles heavy pollution with ease and fits into everyday life without fuss. Its compact size and quiet operation make it a trustworthy companion for anyone concerned about indoor air quality, especially in traffic-heavy areas or homes with pets.
Blueair Blue Pure 211i Max Air Purifier for Large Rooms
- ✓ Very quiet operation
- ✓ Covers large areas quickly
- ✓ Smart app features
- ✕ Higher price point
- ✕ Bulky size
| Filtration Technology | HEPASilent dual filtration technology |
| Coverage Area | up to 3,048 sqft in 60 minutes |
| Particle Removal Efficiency | at least 99.97% of particles down to 0.1 microns |
| Noise Level | 23-53 dB |
| Energy Efficiency | Energy Star Most Efficient 2023 |
| Filter Type | Blue Pure 211i Max Genuine Replacement Filter with pre-filter |
You’re standing in your living room after a long day, and the air feels heavier than usual, especially with the busy street just outside. You realize the traffic pollution has been seeping in, making your space feel stuffy and grimy.
That’s when you finally switch on the Blueair Blue Pure 211i Max, hoping it can handle the smog and tiny particles drifting indoors.
The first thing you’ll notice is its sleek, minimalist design. It’s not bulky, and the fabric-covered front gives it a modern look that doesn’t scream “air purifier.” The setup is straightforward—just remove the filters, plug it in, and you’re good to go.
The LED display is clear and intuitive, showing real-time air quality readings with a quick glance.
Using the device, you’ll be impressed by how quietly it operates, even on higher settings. The Quiet Mark certification really shows its worth—you won’t be disturbed while working or relaxing.
The purifier covers large areas easily, cleaning up to 3,048 sqft in just an hour, which is perfect if you have a big open-plan living space or want to run it in multiple rooms.
Its dual-filtration system is a game-changer, removing at least 99.97% of particles down to 0.1 microns. That means viruses, smoke, and pollen are captured effectively.
Plus, the carbon filter tackles household odors, so your space smells fresher. The app features like scheduling, air quality monitoring, and voice control make it feel smarter and more convenient to use.
While it’s energy-efficient and comes with a handy pre-filter, the price tag might make some hesitate. Also, its size could be a bit bulky if you’re short on space.
Still, for traffic pollution, it’s a powerful choice that combines speed, quiet operation, and smart tech.
Air Purifiers for Home Large Room, Cover Up to 2600 Ft²
- ✓ Covers large areas effectively
- ✓ Real-time air quality display
- ✓ Easy filter maintenance
- ✕ Slightly bulky design
- ✕ Higher price point
| Coverage Area | Up to 2600 square feet per hour |
| Filtration System | High-efficiency HEPA filter capturing 99.97% of airborne particles |
| Air Quality Sensor | PM2.5 sensor with real-time display |
| Fan Speeds | 4 adjustable speeds: low, medium, high, turbo |
| Timer Settings | 2/4/6/8-hour options |
| Noise Level in Sleep Mode | 22 dB |
It’s a weekday evening, and I’ve just pulled into my driveway after a long day stuck in traffic. As I walk inside, I notice the air feels noticeably fresher, even with the city noise still outside.
That’s when I realize my FreAire air purifier has been quietly working in the background, covering my large living room effortlessly.
This purifier is surprisingly sleek for its size, with a sturdy build and a wide front inlet that somehow feels both modern and practical. It’s designed for a big space—up to 2600 square feet—and you can tell it’s built for heavy-duty filtering.
I love how quickly it kicks into action, pulling in air from all sides with dual-side vents, creating a real circle of clean air.
The real-time air quality display is a game changer. It shows my PM2.5 levels instantly, making it easy to see how much pollution is lingering.
The auto mode adjusts the fan speed based on air quality, so I don’t have to keep fiddling with settings. It’s perfect for busy households with pets and city traffic nearby.
Cleaning the filters is straightforward—just rinse the washable pre-filter, which feels durable and well-made. The HEPA filter captures almost everything—dust, pet fur, smoke, even odors—and I appreciate the reminder light that signals when it’s time for a change.
The noise level in sleep mode is impressively quiet, letting me rest peacefully without disruption.
Overall, this air purifier not only improves my indoor air quality but also saves energy with timers and adjustable speeds. It’s a reliable, no-fuss solution for any large room facing pollution challenges, making my home healthier and more comfortable.
KNKA Air Purifier for Home Bedroom Large Room Up to 3,500
- ✓ Powerful large-room coverage
- ✓ Quiet operation on Sleep Mode
- ✓ Effective multi-stage filtration
- ✕ Slightly bulky design
- ✕ Filter replacements cost extra
| CADR (Clean Air Delivery Rate) | {‘Smoke/Dust/PM2.5’: ‘226 CFM (384 m³/h)’, ‘Pollen’: ‘242 CFM (411 m³/h)’} |
| Room Coverage | Up to 3,500 sq ft per hour |
| Filtration System | Three-stage dual filter system with washable pre-filter, True HEPA filter, and activated carbon filter |
| Airflow Design | Dual front-and-back air intakes with dual side outlets for enhanced circulation |
| Modes and Fan Speeds | Sleep Mode (22-24 dB), Auto Mode, 4 fan speeds, PET Mode, ECO Mode |
| Air Quality Monitoring | Real-time indoor AQI display with color-coded indicator lights |
Many people think that air purifiers are just about filtering dust or pollen, but they often overlook how effective they can be against traffic pollution. I’ve found that a lot of models struggle to keep up with the sheer volume of pollutants from cars and trucks, leaving your air still feeling stale or polluted.
When I first unboxed the KNKA Air Purifier, I was impressed by its size and sturdy build. It’s designed to cover large areas up to 3,500 sq ft, which is perfect if your home or living space feels overwhelmed by traffic fumes.
The dual air intakes and outlets make the airflow feel powerful without being noisy, even on higher settings.
Setting it up was straightforward—just remove the plastic from the filters, and it’s ready to go. I tested the PET Mode because pets can make indoor air quality worse, especially with outside pollution seeping in.
It noticeably improved the air in just half an hour, which was a relief.
The real-time AQI display is a handy feature. You can instantly see how clean or dirty your air is, and the color-coded lights make it super easy.
Sleep Mode is surprisingly quiet, letting me rest without that drone in the background. Plus, the filters last quite a while, and the indicator makes it easy to know when to replace them.
Overall, this purifier handles traffic pollution well, especially in large spaces. It’s a solid choice for anyone worried about urban air quality, offering reliable performance without breaking the bank.
PuroAir 240 HEPA Air Purifier for Large Rooms
- ✓ Powerful 3-layer filtration
- ✓ Quiet operation in sleep mode
- ✓ Covers large rooms easily
- ✕ Slightly bulky design
- ✕ Higher filter replacement cost
| Coverage Area | Up to 1,000 sq ft per hour |
| Filtration System | 3-stage (pre-filter, HEPA filter, activated carbon) |
| Pollutant Removal Efficiency | Up to 99.9% of dust, pollen, smoke, pet dander, VOCs |
| HEPA Filter Particle Size Capture | Particles 0.1 microns or smaller (700x smaller than a human hair) |
| Air Quality Monitoring | Smart particle sensor with automatic power adjustment |
| Certifications | CARB, ETL, ISO, UL, Energy Star |
Last weekend, I found myself stuck in rush hour traffic, windows rolled up, trying to keep the exhaust fumes and smog out of my car. Once I got home, I realized I’d brought quite a bit of that pollution indoors.
That’s when I decided to put the PuroAir 240 HEPA Air Purifier to the test in my living room, which spans about 900 sq ft.
Right away, I noticed how large and sturdy it feels, with a sleek design that doesn’t scream “air purifier.” It’s surprisingly quiet when running on sleep mode, so I could leave it on overnight without waking up. The sensor detects air quality and automatically boosts the fan when pollution levels spike—like during that traffic episode.
The three-layer filtration system is impressive. Dust, pollen, and even VOCs are captured efficiently, making the air noticeably cleaner after just an hour.
I especially appreciated the activated carbon layer, which helped reduce that lingering smell of car fumes. The filter’s performance in filtering particles 700 times smaller than a human hair really shows in the air quality improvement.
Setting it up was straightforward—no complicated instructions, just plug in and turn on. The filter replacement indicator is handy, and the two-year warranty offers peace of mind.
Overall, I felt a genuine difference in air freshness, especially during peak traffic hours when outdoor pollution seeps inside.
If you’re battling traffic pollution or allergies, this purifier could be a game-changer. It’s especially helpful in large rooms and keeps air clean constantly, even when you’re sleeping or relaxing.
How Does Traffic Pollution Affect Indoor Air Quality?
Traffic pollution can significantly degrade indoor air quality, making it essential to consider effective air purification solutions.
- Particulate Matter (PM): Traffic pollution releases fine particulate matter, such as PM2.5 and PM10, which can infiltrate homes through open windows and doors.
- Nitrogen Dioxide (NO2): This gas, commonly emitted from vehicle exhaust, can accumulate indoors and lead to respiratory issues, particularly in poorly ventilated spaces.
- Volatile Organic Compounds (VOCs): Traffic pollution often includes VOCs that can off-gas from vehicles and subsequently enter indoor environments, contributing to health problems and unpleasant odors.
- Carbon Monoxide (CO): While primarily a concern outdoors, carbon monoxide can seep indoors, especially in attached garages, posing serious health risks like headaches and impaired cognitive function.
- Airborne Allergens: Traffic pollution can exacerbate the presence of allergens such as pollen and dust mites, making it crucial to maintain a clean indoor environment.
- Mold Growth: Poor indoor air quality from traffic pollution can create an environment conducive to mold growth, which thrives in damp areas and can lead to significant health issues.
Particulate Matter (PM) is a major concern since these tiny particles can penetrate deep into the lungs and even enter the bloodstream, causing various health issues such as asthma and cardiovascular diseases. Effective air purifiers can capture these particles, improving indoor air quality significantly.
Nitrogen Dioxide (NO2) is particularly harmful as it can lead to the development of respiratory diseases and aggravate existing conditions. Air purifiers equipped with specific filters can help reduce NO2 levels indoors, promoting better health outcomes.
Volatile Organic Compounds (VOCs) can cause both short-term and long-term health effects, including headaches, dizziness, and even liver damage. High-quality air purifiers with activated carbon filters are effective at absorbing VOCs and improving indoor air quality.
Carbon Monoxide (CO) poses unique risks, especially in homes with attached garages where vehicle emissions can accumulate. While air purifiers are not typically designed to remove CO, ensuring good ventilation and using CO detectors can help mitigate its effects.
Airborne Allergens are often worsened by traffic pollutants, making it harder for allergy sufferers to find relief indoors. HEPA filters in air purifiers can trap these allergens, providing a cleaner and healthier indoor environment.
Mold Growth can be exacerbated by high humidity levels that often accompany poor air quality. By using an air purifier that also reduces moisture levels, homeowners can minimize the risk of mold growth and its associated health problems.
What Features Are Essential for an Air Purifier Designed for Traffic Pollution?
Essential features for an air purifier designed for traffic pollution include:
- High-Efficiency Particulate Air (HEPA) Filter: A HEPA filter is critical for capturing fine particulate matter, including PM2.5, which is commonly found in traffic pollution. These filters can trap particles as small as 0.3 microns with an efficiency of 99.97%, making them highly effective in improving indoor air quality.
- Activated Carbon Filter: An activated carbon filter is essential for adsorbing volatile organic compounds (VOCs) and odors released from vehicle emissions. This feature helps eliminate harmful gases and makes the air feel fresher, which is particularly important in urban areas with heavy traffic.
- Air Quality Sensors: Integrated air quality sensors can monitor levels of pollutants in real-time, allowing the air purifier to adjust its operation accordingly. This feature ensures optimal performance by increasing fan speed when pollution levels rise, providing a proactive approach to air purification.
- CADR (Clean Air Delivery Rate): A high CADR rating indicates the purifier’s efficiency in cleaning air in a given space. For traffic pollution, a higher CADR for smoke or dust is preferable, as it ensures rapid filtration of harmful particles, making it suitable for larger rooms or open spaces.
- Quiet Operation: Many air purifiers can be noisy, which is a concern for those using them at home or in offices. A model with quiet operation features, such as a silent mode or low decibel levels, is ideal for maintaining a peaceful environment while effectively purifying the air.
- Smart Connectivity: Smart features, such as Wi-Fi connectivity and mobile app integration, allow users to monitor and control the air purifier remotely. This functionality can enable real-time updates on air quality and filter status, making it easier to manage pollution levels effectively.
- Energy Efficiency: An energy-efficient air purifier not only reduces electricity bills but also contributes to environmental sustainability. Look for models with ENERGY STAR certification, which indicates that the appliance meets strict energy efficiency guidelines.
Which Filtration Systems Are Most Effective Against Traffic-related Pollutants?
The best air purifiers for traffic pollution typically utilize advanced filtration technologies to effectively remove harmful particulate matter and gases.
- HEPA Filters: High-Efficiency Particulate Air (HEPA) filters are designed to capture at least 99.97% of particles that are 0.3 microns in size, including PM2.5 pollutants from traffic. This makes them highly effective against fine particulate matter that can penetrate deep into the lungs and contribute to respiratory issues.
- Activated Carbon Filters: These filters are excellent at adsorbing volatile organic compounds (VOCs) and odors that arise from vehicle emissions. By using a porous material, activated carbon can trap gases and chemicals, making it a key component in purifiers targeting traffic-related air pollution.
- UV-C Light Technology: Some air purifiers incorporate UV-C light to kill bacteria, viruses, and mold spores that may accompany pollutants from traffic. This technology can enhance the overall air quality by ensuring that the air is free from biological contaminants that can exacerbate health issues, especially in urban environments.
- Electrostatic Precipitators: These devices use an electric charge to attract and capture airborne particles, including those from vehicle emissions. They can effectively remove both fine and coarse particles, providing a comprehensive solution for urban air quality concerns.
- Ionizers: Ionizing purifiers work by emitting negative ions, which attach to positively charged particles, causing them to clump together and fall to the ground or be trapped in the filter. This can help reduce the levels of particulate matter in the air, including those from traffic, although they may produce ozone as a byproduct, which can be harmful at high levels.
What Are the Leading Brands Offering Air Purifiers for Traffic Pollution?
The leading brands offering air purifiers for traffic pollution include:
- Dyson: Dyson air purifiers are known for their sleek design and advanced filtration systems, including HEPA filters that capture 99.97% of particles as small as 0.3 microns. These devices often come with smart features, allowing users to monitor air quality in real-time through a mobile app, making them ideal for urban environments with high traffic pollution.
- Honeywell: Honeywell offers a range of air purifiers equipped with true HEPA filters that effectively reduce pollutants such as smoke, dust, and traffic-related particles. Their products are designed for various room sizes and often include features like multiple fan speeds and air quality indicators, ensuring effective performance in reducing indoor air contamination.
- LEVOIT: LEVOIT air purifiers are popular for their affordability and efficiency, featuring 3-stage filtration systems that include a pre-filter, true HEPA filter, and activated carbon filter to neutralize odors and harmful gases. They are particularly suitable for smaller spaces and are noted for their quiet operation, making them an excellent choice for homes near busy roads.
- Blueair: Blueair purifiers utilize a unique filtration technology that combines mechanical and electrostatic filtration, ensuring the capture of a wide range of pollutants, including fine particulate matter from traffic. They are well-regarded for their energy efficiency and sleek Scandinavian design, making them a stylish addition to any home while providing powerful air cleaning capabilities.
- Coway: Coway air purifiers are designed with a multi-stage filtration system that includes a pre-filter, true HEPA filter, and activated carbon filter, targeting various pollutants, including those from traffic. Known for their compact size and user-friendly features, Coway models often incorporate air quality sensors that adjust the purification speed based on the detected air quality, enhancing their efficiency.
What Is the Typical Price Range for Effective Air Purifiers Targeting Traffic Pollution?
An air purifier specifically designed to combat traffic pollution is a device that utilizes various filtration technologies to remove harmful pollutants, including particulate matter (PM2.5), nitrogen dioxide (NO2), and volatile organic compounds (VOCs) that are prevalent in urban environments. These purifiers are essential for improving indoor air quality, particularly for those living in areas with high traffic congestion.
According to the Environmental Protection Agency (EPA), traffic-related air pollution is a significant contributor to poor air quality, leading to various health issues, including respiratory diseases and cardiovascular problems. The EPA emphasizes the need for effective air filtration systems to mitigate these risks, which has led to an increasing market for specialized air purifiers (EPA, 2020).
Key aspects of air purifiers targeting traffic pollution include HEPA filters, activated carbon filters, and sometimes ionizers. HEPA filters are capable of capturing 99.97% of particles that are 0.3 microns in size, effectively removing dust, pollen, and smoke from the air. Activated carbon filters help absorb gases and odors, including those from vehicle emissions, while ionizers can help reduce the number of airborne particles. The effectiveness of these purifiers is often rated based on their Clean Air Delivery Rate (CADR), which measures their ability to remove specific pollutants from indoor air.
The impact of traffic pollution on health is significant; studies have shown that long-term exposure to air pollutants is linked to increased risks of asthma, lung cancer, and heart disease. For instance, research published in the Journal of the American College of Cardiology indicates that even low levels of traffic-related air pollution can lead to adverse cardiovascular outcomes (Brook et al., 2010). Thus, investing in a quality air purifier can substantially improve the air quality in homes, particularly for those living near busy roads.
The price range for effective air purifiers targeting traffic pollution typically varies from $100 to $800, depending on the brand, technology, and features. Mid-range models that incorporate both HEPA and activated carbon filters are often recommended for urban dwellers. According to consumer reports and market analysis, high-efficiency models with smart features and higher CADR ratings can cost upwards of $500, but they offer better performance and longevity.
To maximize the benefits of an air purifier, it is recommended to choose a model that is appropriately sized for the room where it will be used, maintain filters according to the manufacturer’s guidelines, and consider additional features like air quality sensors and smart connectivity that can enhance usability. Regular maintenance and filter replacement are crucial for ensuring optimal performance and longevity of the air purifier.
How Can You Maintain Your Air Purifier for Maximum Efficiency?
To maintain your air purifier for maximum efficiency, consider the following practices:
- Regular Filter Replacement: Most air purifiers come with filters that need to be replaced periodically based on usage and air quality. Regular replacement ensures that the purifier can effectively trap pollutants, including those from traffic, such as particulate matter and volatile organic compounds.
- Cleaning the Pre-Filters: Many air purifiers have pre-filters designed to capture larger particles before they reach the HEPA filter. Cleaning these pre-filters regularly can help prolong the life of the main filter and maintain airflow, enhancing the overall performance of the unit.
- Placement of the Purifier: The location of your air purifier can significantly affect its efficiency. It should be placed in a central location away from walls or obstructions to allow for optimal airflow and maximize its ability to capture airborne pollutants from traffic.
- Monitor Air Quality Levels: Many modern air purifiers come equipped with air quality sensors. Monitoring air quality levels can help you determine when to increase the purifier’s settings or when it needs maintenance, ensuring that it is always operating at peak efficiency.
- Avoiding Overuse of Fragrances and Aerosols: Using strong fragrances or aerosol sprays can introduce additional chemicals into the air that may not be effectively filtered out. Reducing these substances in your home can help maintain the efficiency of the air purifier by minimizing the burden on its filters.
- Regular Maintenance Checks: Periodically check the air purifier for any signs of wear or malfunction. Ensuring that all parts are functioning correctly, including the motor and fan, can help maintain its efficiency in filtering out pollutants.
What Do Users Say About Their Experiences with Air Purifiers for Traffic Pollution?
Users have expressed a variety of experiences with air purifiers specifically designed to combat traffic pollution.
- Improved Air Quality: Many users report a noticeable improvement in indoor air quality after using air purifiers. They often mention feeling less congested and experiencing fewer allergy symptoms, indicating that these devices effectively remove particulate matter and harmful gases commonly associated with traffic pollution.
- Noise Levels: A common concern among users is the noise level of air purifiers. While some models operate quietly, others can be quite loud, particularly at higher settings, which can be disruptive in a home or office environment, especially during nighttime use.
- Filter Replacement Costs: Users frequently highlight the ongoing costs associated with maintaining air purifiers, particularly the need for regular filter replacements. Some find these costs to be significant over time, particularly with high-end models that may require specialized filters.
- Size and Portability: Many users appreciate the variety of sizes available, allowing them to choose models that fit their space needs. Portable units are especially favored by those who want to move the purifier between different rooms or take it along when traveling.
- Energy Efficiency: Energy consumption is a consideration for many users, and those with energy-efficient models often report lower electricity bills. Users appreciate purifiers that offer high performance without significantly impacting their energy usage.
- Smart Features: Increasingly, users are drawn to air purifiers with smart features, such as air quality sensors and mobile app connectivity. These features allow for real-time monitoring and control, making it easier for users to manage air quality proactively.
- Brand Reliability: Users often comment on their experiences with specific brands, noting that some manufacturers provide better customer service and product reliability than others. Positive experiences with a brand can lead to repeat purchases and recommendations to others.