It seems there's a Facebook Fan Page and group for just about anything and everything. I recently saw on my feed that some of my friends are fans of napping. I don't really see any rhyme or reason to that, however there are some Fan Pages that can benefit you.
Clarins recently established a Facebook Fan Page where they're giving out free samples of their Multi-Active Day Early Wrinkle Correction Cream to the first 5,000 fans who sign up. Besides information on new products, you can also find out what events the brand is participating in and get the scoop on recent press they've gotten. You can also follow them on Twitter too.
I'm a huge advocate of Facebook Fan Pages that actually provide useful information and offer discounts or free samples to their fans. Looks like I have some work to do on the BeautySweetSpot Fan Page! Giveaways to come!