When you join Twitter, it is a SOCIAL networking community. If you have a name on there which, say, is something like MakesLotsOMoney - and that's not a specific name that I've seen, but I have seen several that are close - and you also have a picture of money as your avatar...
You have a strike against you right there. People on Twitter want to talk to actual people.
And then if, on top of that, you send direct messages and tweets that link to a clickbank product...you're an idiot. And people will unfollow you and not buy from you.
I promote a couple of clickbank products, but I would never try to do it on Twitter.
There are a lot of great ways to use Twitter, but spamming people with Clickbank links is not one of them.