It was just a thought I have several apps that have one very small ad at the bottom of the page and to me I'd much rather put up with that than have to pay for the app to support its makers. Even BYC owners have to eatI don't think it would be all that nice to put adds with this calculator :/
It's a calculator; not a bulletin board.
The site has enough advertisements as it is; they slow my page down and push modules around before I can click on them.