An ad system is based on the concept of provision of contextual ads (or documents in Solr terms) that are related to either the searched keyword or the document being viewed. Ads can also be generated or searched on the basis of the user's profile information and browsing history. The positioning and placement of an ad must match with the space available on the web page. On the basis of these functionalities, advertisements can be broadly divided into the following categories:
Ads based on keywords searched—referred to as a listing ad
Ads based on the placement and positioning available on the web page
Ads based on the user's browsing history and his or her profile—also known as user-targeted ads
To understand how an ad system works, we need to understand the functionalities it provides. On the back end or the admin side, the ad system should provide the following functionalities:
The definition of ad placement or the position where the ad would be able to fit on a web...