I've been an adsense publisher for around three years, and in that time my daily income has increased slowly and then it levelled off about 12 months ago. I recently (in the last three months) started looking at improving income from adsense across a couple of established domains I own, that are reasonably well trafficked, although nothing earth shattering. I have moved the position of adsense ads around slightly to try and understand what makes the most money, normally leaving the ads in palce for 4 weeks to access their effectiveness. The problem : Within any four week period (of the ads staying in the same place), adsense earnings can fluctuate on a daily basis by as much as 66%, making it impossible to access whether the position is effective enough. the net result over a three month period is that earnings have been within around 10% of each other, but I can log in one day and see earnings at 66% of the average, and sometimes 133% of the average. I understand smart pricing can take effect, and the value from adwords will fluctuate on a day to day basis, but I'm having a hard time understanding why earnings fluctuate so dramaticaslly on a daily basis. Visitor levels are pretty constant (+/- 5%) and clicks is probably the same (+/- 5%). Is this just Google adjusting things on the fly, or something more untoward in the whole adsense scene? Its infuriating to see those 133% good days, only to be down at 66% the next day. I'm beginning to lose faith in the way the system works. When I use chitika/widgetbucks, they appear to be more consistent in the daily totals.....
I think it is google adjusting the ads each day. I had one click today for $1.25 on a site that gets 1 to 25 cents per click on most days.