Adserver.Online chooses ads for display from the ads assigned to a particular zone. When ads compete for an impression/click, an ad server runs an auction to choose a winner.
The Adserver platform offers various auction models that cater to different business models and use case scenarios.
Weight
Weight is the default auction model. It uses the campaign Weight value (located in the Advanced section on the campaign form) to determine the probability of winning.
Therefore, every campaign/ad has a chance to be displayed. By adjusting the Weight you decrease or increase the chance of winning.
This auction model is simple and recommended for in-house setups when you don't need to deal with money – you don't fill the Rate field for your campaigns.
Rate
Rate is similar to Weight. However, it uses the campaign Rate value to determine the probability of winning.
Therefore, every (regardless of how high the rate is) campaign/ad has a chance to be displayed. By adjusting the Rate you decrease or increase the chance of winning.
This auction model is recommended for the setups when money is involved so you specify the rates for your campaigns.
First Rate
First Rate model works in a way that campaigns/ads with the highest rate will always win the auction and others will have no chance (compared to Weight/Rate models).
Therefore lower bidding campaigns/ads may not receive any traffic (subject to frequency capping, limits, and traffic volume available).
This model is for use cases when your zones are involved in programmatic advertisement.
Second Rate
If you select Second Rate, the winner of an online auction is the one who makes the highest bid, but the sale price does not equal that bid.
Instead, it equals the bid of the competitor whos rate was the second highest.
For example, if your bid is $2, and the previous competitor bids $1.5, you win the auction but will be charged $1.5, not $2, as in the case with the First Rate model.
This model is for use cases when your zones are involved in programmatic advertisement.
How to configure
In order to select one of the auction models, you should go to the zone's form in the Publisher / SSP section:
Besides, you can use Services / Zone updater for bulk updating.
The default value can be set in the Settings / Common menu.