Online Ad Serving - In the beginning...

In our first post, we did an overview of inventory, supply, and demand.  In this post, we start exploring how ad serving has evolved through the years.  Back when online advertising began in the early/mid 1990s, it was a simple set up with a Publisher selling ad inventory directly to the Advertiser (and/or Agency.  We'll write more on other players like ad agencies later).

After the Advertiser agreed on rates directly with the Publisher to place ads on the site, the Advertiser would send the image for the ad (called the creative) to the Publisher.  The Publisher places these ads on their web pages similar to any other image and load it all in their web server for delivery.  Below is a simple flow showing how a user on a browser is served an ad.

1. User in the browser goes to a Publisher's web site such as www.yahoo.com
2. The Publisher web server returns HTML to the browser to load the page and any images including the ad
3. The web browser fetches content such as images and the ad from the web server
4. The content including the ad loads on the browser

This all seems nice and easy but the workflow was tedious.  Any time an advertiser wanted to change ads or new advertisers signed up, the Publisher would have to make changes to their live web site which was risky and time-consuming.  We'll explore in our next post how the ad server was created to help the Publishers with this.

Note: if you're a beginner to Internet and don't understand the basics of how it works such as HTML, browsers, etc., you can learn more at another blog http://www.learninternetbasics.com.  It's early stages as of this original post but will be built out quickly to provide foundational knowledge to continue with this blog.