Hits – This is an imprecise number that gives an idea of how many times an ad has been viewed. It can be skewed my many factors, mostly by users hitting the “back” and “refresh” buttons in their web browser.
Page impressions or page views – This tells how many times a webpage has been requested from the server. This helps show how many times a specific banner came up to how many times the page was viewed.
Banner views – The other half of the above equation.
CPM – A metric term from print advertising that stands for "Cost Per Thousand." (The "M" is the Roman numeral for one thousand.) A price of $15 CPM means the website owner will receive $15 for every thousand times a banner is displayed.
Creative – "Ad-speak" for the actual banner graphic.
Click or Click-Through – The terms for when you click on an ad and therefore go to the advertiser’s website. This can determine the amount of money the advertiser pays the website owner.
Click Through Rate (CTR) – The percentage of click-throughs to banner views. A 1% CTR means that 10 people out of 1000 that saw the banner actually clicked on it.
Cookies – Chances are you’ve heard of a cookie before. A cookie is registered to your computer when you click on a banner ad. This keeps you from seeing the same ads repeatedly and also helps display other ads with a similar focus.
Cost per sale – This is used by advertisers that are trying to make a specific sale through their banner ad. It measures how much advertising money is spent on making one sale.
Run of Site (ROS) – Running a banner ad on an exchange or website where no actual targeting or thought is put into matching the content.