Oh, Indubitably they are in it for the data. Even if they aren't collecting it into an organized categorized database for that purpose of selling the compiled data outright, it is hardly necessary to do that. Advertising isn't just about what monies are gained from the people who see the ads - there is HUGE money in selling the potential to expose people. They can simply make a fortune by selling ad space to companies based on the fact that anyone who sees their ad is likely to be a potential customer. (Unlike, say, all the spam I get trying to sell me penis enlargement products...) Given what kind of bucks are spent for a 30 second TV spot during the Superbowl, imagine how valuable such precisely targeted ads would be.
The ads that exist now are already targeted to the profile holder when they appear on the page. Very rarely have I seen an ad on FB that wasn't somehow linked to something I might have "liked" or some item in my profile in the basic info page. I began to be a little wary of that when the first big change I noticed was that suddenly all the things I had listed under favorite movies or books or what have you were going to be linked to a page of that thing. I actually removed a great deal of things from my "likes" at that point, but if I wanted to leave anything, I was going to have to live with being an advertising vehicle for them directly since it was link or not like.
I can't say this is a horrible thing, however, even despite my annoyance with the fact that advertising pretty drives all commerce in some way now, as I have already reaped a considerable benefit of this. One of the things i chose to leave (and therefore allow linking to a page) in my list of favorite music was Sting. Turns out, I would never have known Sting was in town were it not for the (very small and unintrusive, even) advertisement which I saw on the top right corner when I logged in to my account to investigate some spam wall post about acai berry that I was pretty sure my friend didn't send. That was 36 hours before showtime... My first thought was that I don't think I would ever have have appreciated targeted advertising were it not for that, and boy was I grateful for it then. I've been kicking myself for missing the Police Reunion Tour ever since I skipped it in an attempt to be responsible and not spend the money.
But generally, I don't mind ads, per se. I don't like the fact that they try to find ways to "sell" us stuff using psychological manipulation instead of making products that we actually want and advertising the product based on its benefits. I still prefer Castrol Syntech motor oil because of that one commercial they used to show where they ran the engines after draining out the oil and the Castrol one kept going. And as it happens, one day I was driving and the bolt on my oil pan dropped out somewhere - along with all my oil. When I pulled over to check when the oil lamp came on, there was not a drop left in the engine at all. I don't know if having Castrol in my car helped or not that day, but that is indeed what I had put in.
But what is really dangerous about FB is the fact that now it isn't just FB that has access to all that juicy info with all the "features" they keep adding which automatically have access to all the info on your profile even from a totally unrelated site, for example, like CNN.com or something. Plus the geographical location apps, and the games (which hardly need to know anything about me or my friends, but need access to all my info?) That worries me some. I've not gotten concerned enough to delete my FB account, because I do like what it provides for me, but I have to constantly crank down on the privacy settings every time they alter something which opts me in by default. I sometimes would like to know exactly what some of the code looks like for the site because I don't really trust that they are as cautious as they should be in making sure there are no holes. I'm pretty sure that already certain apps can be manipulated to access my friends even without logging in as me or knowing who I am.
