According to Buzzillions.com reviews, the Canon (CAJ) G9 Powershot camera is ranked No. 3 in its product category.

But reviews don’t always identify their authors’ true motives. One item might be reviewed by a satisfied customer who bought the product, or it could be from someone who designed the product and wants to see it succeed. A review could even be from a manufacturer’s disgruntled employee who wants to see the product fail. Blogs can perpetuate such biased behavior by inviting people to submit reviews without verifying whether or not the members ever used the product.

This week, I tested Buzzillions.com, a free Web site owned by San Francisco-based PowerReviews Inc. that mainly posts reviews from people who have verifiably purchased the product they are appraising, according to retailers’ records. It also organizes reviews in specific categories, allowing users to search according to how they categorize themselves.

For example, someone shopping for sheets can label herself a budget, midrange or high-end shopper. A guy looking for a videogame console could call himself a gaming novice, casual gamer, frequent player or hard-core gamer. And someone on the hunt for the right shampoo could call herself a minimalist, beauty conscious or a product junkie. Selecting one of these profile labels whittles reviews down to only those best suited for the personality of the person buying the product — or perhaps receiving it as a gift.

The secret sauce behind Buzzillions is generated by surveys that over 300 retailers send to consumers. A few weeks after buying a product, consumers receive an email survey with a link to a Buzzillions questionnaire. These surveys ask consumers what they consider to be a product’s pros, cons and best uses, and its ranking according to the site’s best-out-of-five star rating system. And, following the Buzzillions formula, it asks these verified buyers to categorize themselves. Both verified users and unverified users, alike, can write reviews for the site, though verified users’ reviews are more heavily considered in the “Buzzillions Rank” system.

The “Buzzillions Rank” shows a product’s standing in its particular category, based on an algorithm applied to the survey data. This formulated ranking is based on three things: a product’s star rating; the number of reviews it receives; and the reliability of its reviewers.

Though Buzzillions can’t prevent a person from posting multiple reviews on a product, it does search the site for duplicate content and users can notify the site if they doubt a review’s authenticity. This could trigger an investigation by the site that may involve tracking the Internet address of a reviewer, the times and frequency that a person posted reviews or even calling the person in question.

Buzzillions is particularly helpful when it comes to certain categories of reviews. The Electronics category, for example, is so populous that it must be divided into 17 subcategories with numerous smaller groups in each subcategory. This category can also be searched by brand.

But Buzzillions has its flaws. Not all products can be sorted with personality labels. And I found that some items were miscategorized. A “GPS” category included receivers, car navigation systems and wristwatches, but when I tried to narrow these products by selecting the “Automotive GPS” category, individual GPS data loggers and receivers still appeared instead of car-only devices like those from Garmin (GRMN) and TomTom. Buzzillions said it would correct this error, but products placed in the wrong categories could be highly confusing for someone unfamiliar with a product. Other categories, such as Shoes and Clothing, left me disappointed by the low number of represented brands and subcategories (i.e. shoes didn’t separate heels or flats from the pack).

Nothing is sold on Buzzillions.com itself, though the site does link to partner stores. But some product pages listed only one online store where the item could be bought. Buzzillions plans to fix this problem by listing about five to 10 online retailers per product.

People can use the site in two ways: as members, by signing up with an email and password and entering descriptions to create profiles of themselves and what types of products they like; or as unregistered visitors to the site. I tried both methods and found the member recommendations practical because they pointed out products I may not have found as quickly using searches. As a member, you instantly see a list of suggested products according to your profile as well as receive gift suggestions via email. And even using the site without becoming a member worked well, never making me feel like the best bits were only offered to registered members.

I really liked Buzzillions’ ”Review Snapshot,” a small at-a-glance box that lists pros, cons and best uses for a product. This snapshot also shows a product’s Buzzillions Rank, as well as its star ranking compared with the category’s star-ranking average. I saved a lot of time by skimming these concise snapshots rather than opening every review.

Buzzillions recently created a mobile version of its site, mobile.buzzillions.com, which runs on the iPhone’s Web browser and can be used for quick looks at reviews and top-10 lists. The company has plans to release an actual iPhone app that should be available soon via Apple’s (AAPL) App Store.

The more I used Buzzillions, the more I grew to depend on the site’s signature Buzzillions Rank, which is clearly listed on a big, bright-green badge. The top 10 products in each category are distinctly labeled, with the No. 1 item in a category getting a special ribbon. And this ranking held true to its formula and showed a product’s real standing: I often saw an item with a higher star-rating average receive a lower Buzzillions Rank because they had far fewer reviews compared with products with a higher Buzzillions Rank.

Another helpful stat that Buzzillions displays prominently with each review is the date that it was reviewed. I looked at a pair of tennis sneakers with a top-10 Buzzillions Rank, but some of that pair’s reviews were labeled with dates that were too old to be relevant for me. Electronics fans, of course, would care even more about these dates.

All told, Buzzillions does a good job of balancing reviews and culling the most-appropriate reviews for certain people based on personality traits. It currently has more than 3.6 million reviews, but will most likely continue to grow as more people use and rely on it, making it an even more valuable tool for shoppers.

– Edited by Walter S. Mossberg

• Email us at mossbergsolution@wsj.com. Find this and other columns and videos online free at the All Things Digital Web site: http://walt.allthingsd.com

Digital Cameras

Megapixels: This term describes the highest resolution photo a camera can take. Often mistaken as the most important factor in a digital camera, a high megapixel count — such as 10MP or more — isn’t necessary for the average user unless he or she plans on heavily editing or enlarging photos. Most new digicams offer between five and eight megapixels, which is usually more than enough.

Optical or Digital Zoom: Optical zoom, determined by the physical movement of a lens, matters much more than digital zoom, which digitally alters an image using the camera’s internal computer. Camera companies still try to confuse potential buyers by listing a camera’s total zoom, or the optical and digital zooms multiplied together. Ignore total zoom numbers and instead focus on optical, which now averages around 5x for many new cameras.

Image Stabilization: When generously sized LCD viewing screens started replacing optical viewfinders, they also forced users to hold their cameras at arm’s length, making for plenty of blurry photographs. To remedy this, camera manufacturers have added image stabilization, tools once found only in high-end SLR models. Optical (also called “mechanical”) and digital image stabilization correct for unsteady hands and moving subjects, respectively. Cameras with both types advertise dual image stabilization, which corrects for both situations and costs more.

Mobile Devices

HSDPA and EVDO: HSDPA, or High Speed Downlink Packet Access, is the name for AT&T’s 3G, or third generation, mobile network that operates at roughly the speed of a slower DSL in a home. HSDPA is available in most major metropolitan areas and is seen as the competitor to Verizon and Sprint’s EVDO (Evolution Data Only) networks, though the popular iPhone runs on AT&T’s network using Wi-Fi and EDGE technology rather than HSDPA.

Multi-Touch Technology: Most popularly found on Apple’s iPhone and iPod touch, multi-touch is starting to show up in other products, such as in Microsoft’s Surface, a coffee-table-like computer. Rather than just responding to on-screen touches, this technology enables moving, resizing and zooming pictures and Web pages using one or more fingers simultaneously. Look for many more devices — mobile and otherwise — to incorporate multi-touch in the future.

GPS: Global Positioning Systems are most often found in cars — either built-in or on portable devices from companies like Garmin and TomTom. These gadgets use satellite technology to determine geographic location, and high-end models even display Web content like news and weather along with directions. GPS integration in mobile devices can be used to plot routes in cars, can help users find nearby businesses while on the go and can link friends by showing one where the other is located and what they’re doing.

Digital Music

DRM: Digital rights management is a set of standards that protect the intellectual property rights of online content like music and videos, preventing it from being illegally distributed across the Web. In the past year, Vivendi’s Universal Music Group, Apple and (most recently) Sony BMG said they will start selling DRM-free versions of songs, often for a higher price. In Apple’s iTunes store, these files are called “iTunes Plus” and aren’t restricted like other iTunes content.

MP3: MP3 files are open, without any DRM restrictions. Files that you rip (copy) from your own CDs are usually converted into MP3s, though iTunes users can automatically rip tracks into that program’s special format, called AAC. MP3 files can be uploaded to social-networking sites for sharing with friends and online communities.

These file types are protected by rights that tie them to specific players. Generally, AAC files make up the majority of tracks sold on Apple’s iTunes store and play only on Apple’s iPods; WMA files are Microsoft’s version of proprietary files.

Wi-Fi

The popularity of Wireless Fidelity, or Wi-Fi, brings this technology to more and more portable devices like the iPod Touch and Microsoft Zune and gives companies good reason to incorporate Wi-Fi receivers in new computers — laptops and desktops alike. While available in many flavors, different letters like b, g, a and n stand behind Wi-Fi’s more technical name, 802.11, to help discern one version from another according to characteristics like speed and compatibility. The latest version, “n,” offers the greatest range and speed, and “n” devices are usually compatible with earlier versions.

Televisions

HDTV: High-definition television has now become the standard, capable of displaying vastly better pictures, provided the source is also HD. Today’s more popular flat panel HD televisions are LCDs, or liquid crystal displays, though plasmas still hold their own. Recording HD content can’t be done with a regular digital video recorder; instead, a special HD recorder is required to capture this higher quality content.

480p vs. 1080i vs. 720p vs. 1080p: These numbers refer to the resolution, or sharpness, of a digital display, while “p” stands for progressive and “i” stands for interlaced. A resolution of 480p, known as EDTV or Enhanced Definition TV, is found most often in low-end plasmas or LCD screens. A TV with a resolution of 1080p is currently considered the Holy Grail, and costs the most. But 1080p pictures usually can’t be distinguished from less expensive 1080i or 720p pictures by average viewers at the typical distances from which most folks watch TV.

Blu-ray vs. HD DVD: Blu-ray and HD DVD are incompatible high-definition disc formats that continue to fight a seemingly endless battle to replace the DVD. The Blu-ray camp is led by Sony and the HD DVD camp is led by Toshiba. The two formats aren’t so different, technically speaking, but their very existence is confusing to consumers. The recent decision made by Time Warner’s Warner Bros. to use Blu-ray gives Sony’s side a boost, and now Viacom’s Paramount is rumored to be switching to Blu-ray from HD DVD. Dual-format players from Samsung and LG offer some solace.

Email: mossbergsolution@wsj.com