Not only does it make you look desperate, but Facebook thinks you're spamming people. When you first get an account or if you're making a new one, it's easy to get carried away with the friend requests as you're trying to get it done as quickly as possible, you know, for the gossip. However, if you add too many people at once, Facebook can deactivate your account if they believe that you don't even know these people. Sometimes having too many friends can bite you in the bum.