What is the optimal number of ad units for a page?

Question

Google Adsense

Is there any advice or sound advice on the number of ad units per page? I mean direct and google

Answer 1

In Google adsense, no more than 3 blocks, but the more you put, the cheaper the cost per click. I put a skyscraper in the sitebar and a rectangle for the article itself. In general, here you can watch the visiting card, but in any case, no more than 3

Answer 2

Usually two blocks are enough with proper placement, but it all depends on the type of content, where you can place three more to make it more efficient

Answer 3

1-2 pieces. less is better.
google A-B testing.