RTB (Real Time Bidding) is a online advertising technology which aims to determine the price for displaying ads through a real-time auction. Historically advertising on websites was negotiated in advance and at a fixed price (CPM - cost per thousand impressions).
RTB - Modus operandi
The operating principle is as follows:
When a user browses a web page, the page calls an advertising tag which in turn connects to an Ad Server (ad server)
This server the connects to advertising networks (Ad Network) or online marketplaces (Ad Exchanges). It will then check the current CPM and determines the highest bidder.
The server with the highest bid will have its ads served on the publisher's website.
The whole operation is achieved in a couple of milliseconds.
The objective is to enable advertisers to reach a more targeted audience at a better price.