How many Adsense blocks per page?

Google Adsense

Many webmasters when starting their own Google Adsense Campaign often ask: What the maximum number of Adsense blocks there may be on a page.
I have read that Google would allow to place maximum of three link units and two search boxes on each webpage.
Searching the web to answer also this question and clarify it I found that results may be better with just one Adsense block. Google will show ads in the order they pay out, so the more ads you show, the more lower payings ads appear on your page. If you have several Google places the highest paying ads on top, and lowest on bottom. Most people seem to earn more with just one large adsense block.