Hell yes it does!!
This is a service that I quite enjoy - as we grow up and move on, we can stay in touch with the people who helped to make us who we are. If the information that I choose to put on my profile is sold on, my bad! I should only post limited info if I am very concerned.
As for placing ads on the network, having looked at the system, you don't really get intrusive on peoples conversations, they just use an AdCenter-type algo to identify keywords on your page that advertisers are bidding on - the same as PPC 'Content' network advertising - and serve you ads you may be interested in.
Yes they have a lot of user information - so does any website that maintains a good database and investigates server logfiles / web stats correctly. It's not a given that they will use this to do a Pinky & the Brain act on us. I hope :p