CPM means Cost Per Thousand
CPC means Cost Per Click

Both of these terms are used extensively when buying and selling banner advertising. There are two basic ways that Banner ads are sold - these are either Per Impression or Per Click.

Per Impression - Per Impression advertising means that you earn money based on how many times a banner is displayed on your site. If your website generates 10,000 page views in a month, that means you could potentially display a banner ad 10,000 times in that same month (assuming all pages have a banner ad on them).

When selling/buying Banner ad Impressions, rates are always given in Cost Per Thousand (CPM). So $6 CPM would mean that you would get $6 for every thousand banner ads shown. For that same site with 10,000 page views in a month - if you sold all 10,000 impressions at $6 CPM, you could earn a total of $60 for that month ($6 per thousand x 10 thousand = $60).

Typical CPM rates range from $1 CPM to $20 CPM.

Per Click - Per Click advertising means you get paid a set amount of money whenever a visitor clicks on that particular banner ad.

Per Click Rates are given in CPC (cost per click). So, if your site generates 10,000 banner impressions at $.60 CPC, then you will earn $.60 every time a person clicks on one of the banners. Typical click through ratios (CTR) are around 1%. So, of those 10,000 impressions, at 1% CTR, you would get (10,000 x .01) 100 clicks at $.60/click = $60.

Typical CPC rates range from $.10 CPC to $.60 CPC