Poll: Optimum number of Adsense ad units on your home page?

[potentialgeek]

[This question is inspired by the thread about the Adsense user who reportedly made $1m in 3 mos; his home page apparently has only one horizontal ad unit.]

How many ad units do you have on your home page? 1, 2, or 3? If you tested each, what were your test results? (Please id if you use vertical or horizontal ads.)

Thanks,

p/g

[Mohamed]

I had one sky scrapper in my homepage and my avg was less then per day, I have removed it and revenue jumbed to xx, so I don't have any ads in my home page. In my other pages I use only one ad block which is Large Rectangle(336 X 280).

[sven1977]

Lately, I tested three ad units versus two and found that two ad units are slightly worse for CTR but much better for CPC, eCPM and overall earnings.

Another thought:
What if all publishers at WW would have a conspiracy and agree to maximally put one ad unit (plus link unit, maybe) on each of our pages so that we could fight the dilution of advertising space? Wouldn't that help increase the bids on the ads and increase our earnings?