Seems everyone talks about ctr, why not ecpm instead as its where the money is at, sometimes i change ads on my site and although i do look at ctr i base if i keep the new ad based on ecpm. all my pages have 1 ad unit, a text unit that has just 1 link on it, my ctr is under 2% ecpm over $15, the square 336x280 gets me more clicks but less money. also my page looks better with the 1 small little ad.