"Twitter has an enormous advantage over Facebook in one key area: while people on Facebook tend to friend their friends, people on Twitter tend to follow their interests. The following graph from Twitter is worth far more on a per-account basis because it is directly monetizable in a way that Facebook’s generally isn’t – you can show prophylactic advertisements to Twitter users based solely on the people they follow, and probably get a much higher rate of interest. Compared to other social display ads, Twitter ads, it is rumored, work extremely well."

Facebook users friend their friends AND follow celebrities/brands/products. Facebook also encourages you to share a lot of information about interests and locations. You might also share the same on Twitter, but its not neatly saved as part of your profile.

I'm not sure Facebook will be able to make more money off advertising then Twitter, but if they don't, it wont be because of lack of information about your interests.