I think the question (for this forum or a new string) is really is Twitter more effective than Facebook or Reddit (I'm starting to get more traffic from Reddit, when I submit links into specific sub-groups) than either of the other two. I submit to Digg regularly and have received one or two visitors total, they are dropping off the radar.
Both of them will not work for you unless you have maintained a specific amount of followers who are interested in what you post. Most of the people add and follow unknown people who are just spammers..and a spammer will never ever click on a link of yours so you need to be very specific about that. Try to dd people you know and make new friends.
By the way i prefer Digg over twitter.