Thank you VladdieD for your explanation. I think we have a winner!

They absorb the fees because they hope to earn the interest for a while, and they hope you lose the checks. Once they identify people who cash all the checks right away, they cut them off. It's very smart actually, and we really can't blame them. So, those of you who haven't been cut off yet and you want to keep the checks coming, consider holding on to them.