Forum Moderators: martinibuster
It's something you have to find out for yourself by a process of experimentation.
FWIW, on my site what works best is one block per page, and even then only on pages where the ads work. I tried having two blocks, but the seconf block had virtually no clicks and that affected my site epc. Dumping the second block gave me a greatly improved income. I don't have ads on every page, and I always use channels to see if the ads work. If they don't they get dumped.