How Web Advertising Works
♫ Saturday, April 2nd, 2011
In the beginning, “advertising” on the Internet meant “banner ads” — the 728×90-pixel ads you see at the top of almost all Web pages today (including this one). In 1998 or so, banner advertising was a lucrative business. Popular sites like Yahoo could charge $30, $50, even $100 per thousand impressions to run banner ads on their pages. These advertising rates provided fuel for much of the venture capital boom on the Web. The idea was that sites could start up and increase their page impressions to make easy money from banner ads. If a site could generate 100 million page impressions per month, it could make $3 million per month with banner ad rates at $30 per thousand impressions.
Where did numbers like $30 or $50 per thousand impressions come from? That’s what magazines typically charge for full-page color ads. The Internet took the same payment model and applied it to banner ads.
At some point, advertisers came to the conclusion that banner ads were not as effective as full-page magazine ads or 30-second TV commercials. At the same time, there was an incredible glut of advertising space — thousands of sites had a million or more page impressions available per month, and companies like DoubleClick began collecting these sites into massive pools of banner-ad inventory. The economic principle of “supply and demand” works the same way on the Web as it does everywhere else, so the rates paid for banner advertising began to plummet.
Let’s look more closely at what determines banner ad rates.

