With an eclectic following of nearly 20 thousand followers from many areas of internet and real world commerce, entertainment, science and the arts, Socialhello gets a lot of response to tweets in the form of real, live people clicking on included links. When I send a tweet for you, real people are going to read it. They are very interested in links to things they can see.
BONUS: Your ad will also be tweeted on additional accounts, also very active, bringing the total number of followers that will potentially see your message to about 30,000.
Limitations - What the user will and will not tweet about.
Anything but hate, adult entertainment and religion.