Hi guys, i saw a google ap. it says people are looking to left side firstly. i changed my ad placement couple of days ago to left side of page and my earnings started to increase. So try this in your websites. I hope this can be helpful for you. a sample page from my website.
English reading people read left to right, therefore that should be correct in theory. 90% of navigations start on the left side of websites, so that's all people really look for. Speaking from experience of course, I'm no ad expert.
Hmm.. I just changed my sidebar to left side... lets see the results.. will comment here in couple of day
Yeah the "google heat map" is great but remember you should try multiple positions for ad placement on the heat map as it is an aggregate so results vary across different sites.
I ran an A/B test on one particular page...the page would randomly show the 160x600 on the left side or the right side and there was a significantly higher click-through on the left side. Ran the test for about a month to collect a statistically significant data set and it was pretty telling.