Looking at the last two pages of your post history I see that you posted mostly one liners, and other very short posts.

You explained yourself as to why you were banned. "Insubstantial posts+sig ad (14 days)" - you were making pointless (insubstantial) posts while getting paid for making each post.

Ironically the signature campaign that you joined on your last post before you were banned would likely have not paid you because of your spammy posts.

Out of curiously did you delete your signature yourself or was that already done for you?