Note on twtad front page...... IMPORTANT: You must abide by the TOS. Violation of the TOS will result in immediate deletion of your account. Below is an excerpt of the TOS. You should read the TOS if you haven't.
4. Publisher Account
(a) You can only post ads from twtAd to a real, valid account in a microblogging or blogging service or website. A real, valid account is one in which you carry out real social conversations, posting your ideas or views, or updating your status or news events to other users, collectively referred to as valid posts. An account containing mostly ads is not a real, valid account.
(b) There must be at least five valid posts between any two ads, from twtAd or any other advertisers. You will not post the same ad more than once in a 3-day time period.
(c) You can only post ads to a real, valid account using the Post Ad function within twtAd. You will not copy or alter the ads in any way, and will not post any ads from twtAd in any other place on the Internet and will not transmit any ads from twtAd by any other means, including, but not limited to, email and IM. (d) You will not click on an ad you post, and will not encourage, mislead, ask, trick or induce in any other manner, your followers or any other users to click on ads you post.
(e) You understand and accept that if twtAD determines in its sole discretion that you violate this TOS in any manner, your account will be immediately deleted without warning and you will not attempt to register for another account on twtAd. You understand and agree that when your account is deleted from twtAd for violation of this TOS, all your earnings will be forfeited.
Still have not been paid I do think this is a scam