According to Reuters, the NYTimes will pay Primedia $410 million for the network of content sites. That's a lot of money.
Presumably the newspaper publisher will use the site for content distrubtion, as a traffic driver and an advertising network/vehicle. It's a move out of the strickly newspaper realm into a broader Internet content platform, which might be seen as akin to a network of content-specific blogs.
According to Amazon.com's Alexa traffic ranking, NYTimes.com comes in at 89 and About.com at 72.
Previously, About.com featured Sprinks' content targeted ads on its sites. Sprinks was acquired by Google, which now provides the contextual advertising for About.com. The NYTimes uses AdWords/AdSense, as do many newspapers.
About.com changed its strategy awhile ago, from being a meta-destination site to what are effectively separate content sites that can be found individually in search engine results. About.com, which began life as The Mining Co., never really lived up to its early promise. Primedia paid $690 million for About.com in 2000.
See Paid Content interview with the head of NYTimes Digital.