Overview

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.

Client-side Wrapper

Most client side wrappers work using the below flow:

1. A client-side wrapper will make requests to one or many exchanges (SSPs and/or DSPs) via end points from the browser of the user.
2. Each exchange will perform an auction.
3. The wrapper will compare the final result of each bid response and select the highest value.

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: 

• Control partners directly on page or via UI
• Open source solutions available
• Free if implemented by the publisher
• Easy to implement a new source of demand
• Reduced latency by calling all demand sources at the same time

Disadvantages:

• May have limitations to the number of bidders used for performance
• Requires development work

Server-side Solutions

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: 

• A single auction
• Improved performance
• Better control of timeout
• Reduction of number of calls
• Transparency of bid landscape (in most cases)

Disadvantages:

• Cost of servers or third-party services providing the servers
• Need to use a user id syncing system
• Increased requirement for development work