Thanks for all replies. Still no change in my stats. i think this is stable and really good money. Normally i earn 10 - 60 cent per click.
From my three month experience in this field, I have learnt the following things also: 1. Click itself gives different amount as PPC depending upon the time spent by the clicker on the Ad page. If you click and close immediately, the PPC is less as compared to the click follow sufficient time given to keep the ad page open and study it. Thus if a person has real interest in the ad and after opening it he surfs the page for some time, the value for the publisher increases. 2. What time of the day the click is made also makes some difference. I was studying CPC of keywords on adword page and suddenly found that after 10 pm, the value of CPC has decreased drastically, in some cases it reduced to 10%. Therefore, I think where someone gets higher value say $5 or more per click, it may be due to the above reasons also.
I had a freakishly high click of over $6 the other week. I wish I had any clue what the keywords were because my site's don't target high paying areas on purpose. I guess just enjoy it and hope for some more!