I prefer Facebook. I've used Twitter a few times and I really don't like it. Facebook has more advanced features.
Followers come and go with both sites. I think it's best to just backlink through the sites and just wait untill you have a decent fanbase.
Facebook tends to perform better for me than Twitter. Although, coming to think about it, i've never purely advertised with Twitter :\
I love twitter I have 1000+ accounts Accounts up to 6000 Followers I love marketing in twitter as it gives me the best of best
but may be bit complexcity comes with lots of benefits than twitter so as if now facebook is much more superior
I'm prefer facebook, user friendly, wall to wall function, include advertising pay per click and so on