PLease do clarify what if none of the ads is being clicked by any of the visitors?… But for instance,the page is having a lot of visitors… Will adsense pay just for displaying ads on a page – which is viewed by lot of ppl?
You’re asking about CPM ads. CPM stands for “cost per 1000 impressions.” Advertisers running CPM ads set their desired price per 1000 ads served and pay each time their ad appears.
CPM ads can only be server on a page if a Adwords advertiser bid for placing CPM ads and place higher bid then CPC ads. So it is a rare scenario, that you get CPM ads on your pages.
My experience is CPM ads yeild high revenue, even some time tripple the CPC ads. CPM ads in Google Adsense compete against pay-per-click (or CPC, cost per click) ads in the ad auction, so only the highest performing ads will be served to your pages. If an advertiser wants to specifically target your site, they will need to bid high enough to beat out the CPC ads that are already in the auction in order to show up on your page. Google pays you each time a CPM ad is shown on your page. But you won’t earn additional revenue for clicks on these ads.
If you’re interested in CPM ads, there are many CPM alternatives to Adsense, Problogger has a good list here of Adsense CPM alternatives.