Distinguishing CPC based ads from CPM based ads

Sidharth asks:
1. How do we distinguish between cost-per-click ads and cost-per-1000 impressions ads?
2. In case of cost per thousand impressions ads, how do we get paid? I mean, after 1000 impressions do we get some money into our account automatically?
3. What if I want to select only cost per 1000 impressions type of ads?

Answer:
Here are your answers.
1. You can’t distinguish (at least by documented means) between CPC / CPM based ads. Thinking that only image ads are CPM based is not true. There are also text ads that are CPM based. Advertisers are given the choice to make there ads either CPM based or CPC based.

2. CPM based ads generate revenue when ever they are displayed. The revenue generated would though be very small.

3. In order for a CPM based ad to appear on your site, it has to produce an effective CPM (perform) greater than the sum of the individual text ads that would otherwise appear. Google has an ad serving system that serves the maximum performing ads. So if you ads are not getting clicked by your large traffic, the ad serving program may try switching your ads to CPM based ones.

Alternately, you can mail the adsense team to serve you CPM based ads only.