try both because i cant say which will work for you after than chose the whichever works for you and leave the other
Idk what kind of marketer you are, but using twitter does not require you to "need a large follower base" I get thousands of unique hits to my campaigns w/o having 1 follower, and these are all targeted hits.
Facebook is probably easier to start out with. Not to mention that maybe once you build up an audience on Facebook you could promote your Twitter on Facebook to get others to follow you
Both. I use both of them for any site that I create. Facebook and Twitter are a must! Facebook is better though.
Both. You don't have to choose one over the other. Although facebook and twitter are quite different from each other, both adds traffic to your site once utilized properly.