Good on you simon, ads are respectfull and not a pain the the a**. Nice format i know where i will be clicking. Wait what is the format of google ads? Pay per click?
Neospector The Powder Toy should have merchandise, but I would not suggest that design. People might confuse it with Dan-Ball's "powder game." Besides, TPT is much more than stick men. If you want a game that has a stick man, then just search "games."
Maybe you could have a shirt that shows a save that uses a lot of different elements and has words with arrows which points to the various elements. That would get peoples' interest. Then have the URL at the bottom.
Sorry, I try my best. Maybe it could be a funny scene on the shirt?
I love games like TPT, and chances are so do you. However, many people do not see the potential/fun in games like this. It might be best just to add a donation button, but most of us are teenagers and can't donate. So... what do we do? (Is money a serious problem?)