A wrapper in the context of digital advertising is a JavaScript Library (or container) which allows digital publishers to make simultaneous bids to multiple buyers and mediate (allow competition) between these buyers, choosing the highest bid response as the winner.
The most popular Header Bidding Wrapper is Prebid, Sharethrough is fully supported in Prebid.
Most client side wrappers work using the below flow:
Note: The wrapper (in most cases) will then communicate the winning bid to the publisher's ad server for further mediation (competing against direct sold campaigns for example).
Benefits:
Disadvantages:
A server-side wrapper is identical in behavior and functionality to a client-side wrapper except it is capable of consolidating the requests to multiple SSP end-points into a single request to the server-side end-point.
For example, using 3 ad slots as an example a publisher would have to make 3 requests to SSP A and 3 requests to SSP B for a total of 6 requests.
With a server-side wrapper these 6 requests could be consolidated into a single request, containing all the required information for 3 ad slots multiplied by two SSPs. The server-side wrapper would then return a single response with the highest bids from both SSPs for each ad slot.
Benefits:
Disadvantages: