Enter the comment ratings, this expands the landscape of discoverable data points about users by now allowing Facebook to let the user community vote on the merits of other users comments, this is important as it allows Facebook to isolate those people that are deemed by their peers to exhibit key influence, these highly influential people are the people who's recommendations are likely to spawn a wave of similar activity in their friends and friends of friends, the comment system shines a light on this activity that has been going on and remained invisible to the previous social data points that Facebook was mining. The combination of comment ratings and the ad targeting system now allows Facebook to simulate something much like what is possible on Twitter. Many major and minor Celebrities , Sports stars and Politicians are making a little change selling sponsored tweets..these celebrities usually sign up with a service that manages the bidding of the ad tweets made available by the celebrity and then they sit back and rake in cash as businesses bid to buy those tweets from the various celebrities. Imagine an air conditioning retailer that sells GE exclusively getting the ability to by sponsored tweets by retired head of GE Jack Welch and you get the idea.
Facebook comments invert this by taking the actual influencial person out of the monetary loop, the influential person does not get paid a dime for their "services" rendered to Facebook other than continuation of the "free" service. However, I gather the gains coming Facebook's way from differentially pricing advertisements to particularly influential people will be beyond anything that we are seeing today as earned by Google using their Ad Sense or by the Twitter services like Magpie and the Celebrity sponsored tweet services. An ad buyer will be able to bid on influential people anonymously it would be in Facebooks best interest to keep this part of their mined data private as if those with influence discovered just how influential they were they might try to extract a cut of the profits from Facebook or forfeit the service. The latter option becoming increasing unlikely as users build up influence and a network that they would be loath to leave, so Facebook has them by the hook. They get to measure the influence by noticing how people comment rate their posts and writings but they earn no share of the resulting visibility for the ad targeting system....this is the holy grail of ad targeting now being born.
Facebook will probably gather metrics on the comment ratings for a time before actively feeding that data into the ad targeting system to refine the results and we can expect a revamp of the ad tools to include some option to purchase ad space on influential persons pages (without naming who they are)...this is when Facebook's ad revenue goes from the current Mach speed to Light speed.