Angie’s List
Since 1995
Users: 1.7 million

Cost of business registration: Free. However, businesses that advertise are listed at the top of reviews for consumers, but are marked as advertisers. Businesses can advertise in Angie’s List online listings, in the magazine, or with the call center; those that advertise must provide a discount to members.

Who can review: Consumer members ($39 estimated annual membership) and non-members. Non-member reviews are marked on the site and not included in the overall grade for a business. Reviewers are asked to rate: price, quality, responsiveness, punctuality, and professionalism, which contribute to a business’s overall grade; reviews where no work was completed account for 20% of a business’s overall grade. Users are prompted to submit reviews.

Business response: If a review dispute is satisfactorily resolved, the negative review is removed. If a member reviews a business at a C or lower rating, Angie’s List asks if the member wants to use the site’s complaint-resolution service.

Mobile: Not disclosed, app for members.

Judy’s Book
Since 2004 
Users: 499,000, including sister site; 500,000 monthly visits; 1.17 million page views

Cost of business registration: Paid businesses have certain access, including adding photos and keywords, and notification of reviews. $19.92 per month for a basic plan; $79.92 per month for a Pro Plan. 12 billion businesses listed, 20% are in the home category — includes company profiles and reviews aggregated from other sites such as CitySearch.

Who can review: Registered users save businesses to a list and add and view friends’ lists; reviewers provide overall 1 to 5 rating; reviews go through a fraud filter and are read by Judy’s Book staff before being posted online.

Business response: Unpaid businesses are allowed one review response; paid listings are allowed unlimited responses. Judy’s Book encourages businesses to respond to good reviews.

Mobile: 20% (and growing) users from mobile devices; no app.

Since 2004
Users: 100 million unique monthly visitors; home and local services category is 11% of reviewed businesses.

Cost for business registration: Businesses can claim a profile by setting up a free business account; add photos, respond to reviews, track traffic; Yelp logos can be used on a business’s website to hyperlink to their Yelp listing.

Who can review: Users with an account (free); 45% of Yelp searches are from its mobile apps; mobile app used on 9.4 million unique mobile devices a month as of January 2013.

Business response: Businesses can send a private message to the reviewer or add a public comment.

Mobile: 45% of Yelp searches are made using its mobile apps; mobile app used on 9.4 million unique mobile devices per month as of January 2013.

Google Places for Business
Since 2005 (as Google Local Business Center)
Users: 191.4 million Google Sites unique U.S. visitors in December 2012; 10 million businesses registered — aggregates business listings from other online directories and searches.

Cost for business registration: Free

Who can review: Users with a Gmail or Google+ account; business listings.

Business response: Businesses create a free business account to confirm address, add photos/videos, coupons, respond to reviews; registered businesses can respond publicly to a review; Google offers review-writing guidelines for users and businesses.

Mobile: Not available, but says mobile access is increasing.

Yahoo Local
Since 1994
Users: 627 million unique visitors per month on Yahoo-branded sites

Cost for business registration: Basic business listing is free (1 photo and a website link); enhanced listing costs $9.95 per month (includes up to 10 photos, a description, and a performance report).

Who can review: Users with an account. Listed businesses are not allowed to review their own company or other businesses.

Business response: There is a report-abuse button. Yahoo’s customer service will look at the review and make a decision. No guarantees to remove the review.

Mobile: N/A

—Nina Patel is a senior editor at REMODELING. Find her on Twitter at @SilverNina or @RemodelingMag.

The Rest of April's Cover Story:

Online Review Sites topic page

Necessary?Evil?: Online review sites are here to stay

Sites for Sore Eyes: Consumer-driven sites leave contractors no choice but to play the game

Optimized Engagement: SEO experts explain how reviews can boost your online visibility

I heart Angie (Not): Contractors' love-hate relationship with the online world's biggest player

Leading Lights: A shifting definition of what constitutes a lead

Friend or Faux?: Despite fake reviews, consumers are stll believers—for now

Friendly Recommendation: Word still spread quickly via the new wave of review sites that use media

Good Word: Why you should (or shouldn't) pay for positive reviews