Adsense Running out of Ads

or what?

[ElvisFan]

Over the last week I have noticed many more PSA on my site which of course has decreased my bottom line.

Could adsense run out of ads because my impressions have tripled over the last week.

It seems less is more with adsense..

I have deleted ads from very low conversion pages but alas still many pages just generate PSA

Any suggestion?

[europeforvisitors]

Does your site cover a very narrow range of topics?

Are there a lot of other sites covering those same topics?

Maybe it's a simple matter of supply and demand--i.e., too many publishers chasing after the same small pool of advertisers, with the publishers using up their allotments of ads for each.