Twitter is the second social networking sites which come after facebook to getting traffic, by using some important steps like interesting profile and share useful information with your friends.
follow a lot that is related to your niche.. add relevant and useful information to your page for others to get attracted to it..
I think twitter is uneffective for traffic generation It's good only for hidden marketing but also with a a stretch!
Do not focus on maximum no. of followers on twitter focus on quality followers who appreciate and RT your tweets. Read mashable.com blog everything is explained about how to work on twitter. All the best
Twitter is still a relatively new social networking sites, and there are still thousand of marketer who are not using it to its full potential.