Hey Elisabeth, I do yes, but then this is more based around my own preference. I personally use Facebook purley for friends. I wouldnt want people outside of this circle to find the content I post on there, I actually go to pretty extreme lenghs to lock my personal Facebook down so its totally private.
As I say though, I am maybe old school in this respect and its just my way of enjoying the site.
For brands however, it represents a great oppurtunity. Since Facebooks aggressive monetisation, it is harder and harder to get found, so unless, as you say, the spammers tainte it (as they may well do ;-) It represents a great new oppurtunity :-)