It’s impossible to visit a website these days without seeing a banner ad. How are people making money off of them? Well, you need to understand three terms: exposures, click-throughs, and registrations. Every time someone sees a banner ad on a site, we call that an exposure. Content providers typically charge around a penny per exposure. So, if you put your banner on a site and it gets 4000 exposures, you owe $40. Click-throughs work differently. They only count if someone actually clicks on your banner. You will usually be charged ten cents per click through. Registrations are the most expensive, but also the most valuable. If someone clicks on your banner and actually buys something or signs up with you, content providers typically charge one to three dollars.
I’m Eric Spellmann taking you to the Next Level.
More Information
What is a Banner Ad?
http://en.wikipedia.org/wiki/Banner_Ad
How Banner Ads Work
http://www.howstuffworks.com/banner-ad.htm