Which earn more? Left side or right side ads?

With the ongiong debate about which side to put your ads left or right.

I had a little experiment myself, and here is the result

            Views   Clicks   CTR   CPM    Earnings
August stats (left side ads)
Blog 1  25,301  315    1.25%  £0.64   £16.15
Blog 2  481       11      2.29%  £9.45   £4.55
Blog 3  6,323    485    7.67%  £2.28   £14.39
Blog 4  902       17      1.88%  £3.22   £2.91

September stats (right side ads)
Blog 1  28,765  410    1.43% £0.63    £18.18
Blog 2  533       5        0.94% £0.46    £0.25
Blog 3  7,941    278    3.50% £1.40    £11.08
Blog 4  988       20      2.02% £3.77    £3.73

As you can see the results varies between different, but it does look in a bit favour to the left in revenue wise.

In conclusion, the left hand side ads does get more notice, but the right had side ads is where most users kept their mouse point, so I guess they cancel each other out.

I feel that different placement of ads suits different sites, I would be happy getting a 3% click through rate, so if your site do an average of 3 to 5 %, I won;t try and change anything.