I actively dislike Facebook. There are serious privacy issues, I rapidly grew tired of all the "XXXX has a carrot from their farm to share with you" messages and the like when I tried it, plus I found very little actual utility to it. What is equally annoying is that Linden Lab is turning lemming by trying to make Facebook a part of their service experience.
Attention Corporate Overlords: There is no need for me to use Facebook to enter your contests, apply for your coupons or product rebates, or to show my loyalty in any way other than continuing to give you my money for your product or service. If you want to give me information, it can be provided via e-mail, your Websites, or other forums that do not require me to risk identity theft, expose me to personal attacks by people with more time on their hands than they have morals in their being, or require me to remember one more password. Please do not continue to marginalize Facebook non-users. Treat us with respect and we really will "like" you.