A little stat: for a month, I ran a skyscraper google ad with 2 ads instead of the skyscraper google ad with 4 ads on a website. Clickthroughs went down from 0.4% to 0.3%. The detailed stats make me believe this change wasn't a random fluctuation, but due to the change. (A change from 0.4% to 0.3% clickthroughs means a 25% decrease in revenue. )
# Dec 26, 2004