I found some interesting data in my adsense report today. The day just started and I have 1 impression with 1 click. The earnings says $0.05 but the eCPM says $47.60. If you multiply $0.05 by 1000 you 'should' have my eCPM ($50.00) but Google says my eCPM is $47.60. AdWords users can only bid to 2 decimal places, correct? So does this mean that Google's commission is exactly 4.8%? Not that this will help anybody make money but I found it interesting.
nope. That is just a rounding error. .0476 round up to .05. Bids are only to the nearest penny, but the actual amount paid is fractions of pennies.
I wonder why are you going in such minute details Let google handle your decimal places , may be they use some other parameters to judge the value. ~Fairy