Difference between CPA and CPM

CPA program in which you advertiser and pay the company for each action done, such as form filled or signup or any free programs, or as publisher affiliate you earn for each task done or each lead generated thru your site, where CPM means earning money form your website using a banner and each time a visitor comes to your site, they see banner and you earn something, and advertiser pay for each valid view on their banner

I didn't know about CPA & CPM. This thread is informative for me. thanks.

Is a CPA or a CPM basis more cost efficient for your specific campaign? To find out, you must express CPMs and CPAs using consistent factors. Express CPMs in terms of acquisitions or CPAs in terms of impressions or CPMs (the industry standard). For today's exercise, total advertising costs only include the media expense. Also, these formulas are useful if you buy only on a CPM basis but track acquisitions.

CPM stands for Cost per Mille or thousand; M is the Roman numeral for thousand. This type of ad campaign is purely based on numbers, with the cost of the ad determined for 1,000 page impressions (each time the ad is shown). An advertiser using CPM ads will be quoted a guaranteed number of page impressions for the ad, and then the cost will be set based on the number. For example, if an ad site has a CPM rate of $10 and guarantees 100,000 page impressions for the ad, the cost to the advertiser will be $1,000 ($10 x 100). Publishers are paid a share of the revenue generated by the site selling the CPM ads, which is usually around 45% or $450 for 100,000 page impressions from our previous example.

Its quite new for me,and i also come to know about that...Thanks...

Thanks for sharing..