If you haven’t yet embraced twitter, or if you haven’t yet grasped it, then you will not have reaped the benefits of the infamous hash-tag (#).
By using it on your posts, people searching that topic will find you! For example, you sell books, so you leave a status about the latest book in and you use #books at the end.
A book lover is searching ‘#books’ and they end up on your page. Simple, but effective.