I know I am not the only person wondering about this... you check your earnings for the day and it's a nice amount - not incredible, but a nice total - then you check an hour later and it's half or less what it was. That can't be all invalid clicks, can it. And the huge discounts have only been seen in the last month or so... previously it would be a matter of a $1 or $2 difference. Any ideas?
That's because you should not talk about today's earnings, only about yesterday's earnings since they are quite definitive unlike today's earnings which are fluctuating all day long.
I think you might be wasting valuable time checking your earning everyday. Rather, check it weekly at most, then use the remaining time on content, link building and other on, off optimization techniques that are legal.
some ad network don't show today's earnings, you can only see yesterday earnings, infolinks for instance.. That way the earnings don't fluctuate at all, I personally prefer adsense's way.
it really depends on how well the ad's are matched with the use that clicks let say the search on google for youtube alot then come to your site and you have a youtube add now pending on what there paying let say max per click is $5 chances are that click will give you $4.50 or more as it a related user...