Which one earns most, Left or Right Column?

[nickdime]

Which particular column does pays the most for each click in google Adsense? The right or the left.

[motionz]

Well actually it depends on many things such as demographics, language, reading direction etc. But in the case of english language users the left column pays the most per click.

[brian]

I conducted an experiment the last year to determine which is the best. So, far from seeing all the metrics and results I will agree with the admin that left column wins.