Display Relevant Advertisements

Let us imagine, the user has entered the search query as "computer" and system finds 5 advertisements related to query.

We do a sum of the budgets of all advertisements. In this case - Sum = 10 + 20 + 30 + 40 + 50 = 150

Now , rand function will generate random number between 0 to Sum. In this case, 0 to 150

Then , we calculate display range for each advertisement using budget. Range for Adv1 is 10, same as Budget. For Adv2 it is 11-30 as budget is 20. If the random number lies in the range 11-30, Adv2 gets displayed and so on.

Probability based model is used to display advertisements. A low budget add would also rendered but with less probability than others.

System also monitors clicks and impressions for each advertisement.