About.com is a database of how-to guides and informational pages. Unlike crowd-sourced guide services, About only uses guides written by credible experts hired by the company. About.com picks its guides to write in certain subject areas. Their work is then overseen by a professional editor who copy edits, fact checks, and offers advice to improve their writing.
About's business model revolves around advertising and being listed in search results. Each topic page has its own contextual ads that are usually related to the topic. Users are then free to access the content without having to pay a subscription fee of any kind. About can almost be thought of as the anti-Wikipedia: the only user-generated aspect of the service is its forums, where users can discuss articles, or any other topic with other users and guides.
The beauty of About.com is akin to that of most other wikis: you can find almost anything there, from how to poach the perfect egg and dating and sex tips to reviews on products and services. The on site search isn't ideal and the ads are prominent throughout, but there's certainly a plethora of information in there to be found. However, while some areas fare better than others, the scope of the content seems to limit the depth on certain topics.