It doesn't mean how many people saw it, just the number of times it was shown. CPM Cost per thousand impressions. So, for a thousand impressions you should get about 50 visitors. It means you will get paid for the number of banners shown on your site. Click-Through Solutions Specialists.
Impression is when the ad banner is viewed by a visitor.
If your Web site is not for a targeted audience, if you just care about traffic, you may benefit by selling banner advertising. If you want to sell anything other than advertising then look for other ways of Web promotion. You will always lose more in lost sales than gain in selling banners. We have a good relationship and very positive experiences with them. You may customize the values of the above three variables to suit your website.