What is Post-bid and what is it for?

Implementing multiple external monetization networks can give you a splitting headache sometimes. Take a fast look at this process: get multiple tags, define priorities, add passbacks, etc…a pain Publishers know very well. Post-bid eases this process by using Prebid.js to simplify everything.

How does Mediation work?

Mediation is the traditional way to implement multiple networks. Basically, it creates a waterfall where a tag is first called (the one with the highest price) to serve an ad. In case there is no ad to serve, it serves another tag (or passback) to the following network. This process goes on until there are no more networks or an ad is served.

Its main drawback comes at the ad ops level as per its implementation, lack of real competition among networks and the great latency it adds. This latency may cause the last tags never be called as users leave the site before.

How does Post-bid work?

  1. The site sends an impression to our ad server
  2. The ad server selects a winning tag; in this case the Post-bid tag
  3. The Post-bid tag is served in the page. This tag uses Prebid.js to make an auction among all sources we have integrated at the same time, thus avoiding a waterfall as all calls are made simultaneously. Afterwards it serves the ad of the highest paying source.


  • Reduces waterfall. All networks are called simultaneously.
  • It makes all networks compete, serving the one that pays the highest price.
  • There’s no need to implement a tag for each price for each network, as the price can be dynamic.
  • No latency so there are less impressions lost due to delays.
  • No passbacks needed, though you may configure one in case Post-bid does not serve any ad.


  • In order to add a network, it must have an adapter in Pre-bid. Click here to see a list.


Tech Experience

No advanced technical knowledge is necessary to implement neither Mediation nor Post-bid.


Post-bid adds very little latency as calls are made simultaneously while Mediation adds a whole lot more as calls are made through a waterfall.
Please note this latency occurs in the ads load not in the page load.


Post-bid makes all networks compete in parallel. The highest paying source wins and gets served.