When server-side wrapper solutions made their entrance, namely via Google’s Exchange Bidding, Amazon’s TAM product and Prebid Server, publishers with concerns around latency rejoiced. In server-side solutions (aka server-to-server or S2S solutions), they saw an opportunity to increase demand for their inventory—particularly mobile app and video inventory—while simultaneously reducing latency. While there are unique complexities for mobile app and video inventory, I have seen S2S solutions generally empower publishers to unify their auction around this inventory, reduce latency, and increase demand.
S2S is not without complications, however. Based on my client conversations and industry experience, I am seeing a few interesting shifts that are impacting S2S adoption.
What Seems to Benefit Publishers? Hybrid Solutions.
Over the past year-and-a-half, I have spoken to many publishers who have seen increasing gains by using multiple wrappers. The strategy that has worked best with the majority of publishers I have seen is a hybrid approach—meaning a combination of client-side and server-side wrapper integrations.
A hybrid approach allows publishers to maximize the demand for their inventory and still be cognizant of potential latency. It provides the best of both worlds. However, one common drawback is the difference in match rates between client-side and server-side integrations.
Matched Users are King
Matching a user means a buyer matches an incoming user cookie with one they have already identified. Because the buyer knows the user, they are generally willing to pay more than they would for an unmatched user. The key difference with matching users on the client-side versus server side is how pixels are synced for buyers.
With client-side integrations, the demand partner has their code on the publisher page. As a result, they are able to control how often pixels are dropped and synced, increasing the match rates. In contrast, with server-side integrations the owner of the wrapper is responsible for pixel syncing on behalf of the partners in the wrapper. This can lead to slightly less control for demand partners which understandably has slowed S2S integrations.
S2S and Client-side Integration Differences
With S2S integrations because the owner of the wrapper is responsible for syncing all other partners, the wrapper needs to sync pixels to increase match rates. In addition, a second hop is created. The extra step results from the pixel drop and sync that happens between the demand partner and the publisher page. The flow now goes between the demand partner, the wrapper solution and then the publisher page. The added travel time means opportunities could be lost.
Additionally, client-side solutions are more developed than server-side solutions because they have been around longer. There are currently over 100 client-side adapters available for Prebid, but on the server-side there are only 15-20. I expect this to change in the coming months, however, it impacts the immediate adoption of S2S solutions.
The Role of Mobile App and Video Inventory in S2S Adoption
With the entrance of Prebid Server to the market late last year and the continued focus on mobile app and video inventory, demand partners and publishers with concerns around control now have an open solution they can build off to better monetize mobile and video inventory.
Mobile app and video inventory typically are more sensitive to latency due to video file sizes and mobile device connectivity constraints. S2S solutions go a long way toward solving for these, but they still lag in matched users for demand partners, whether matching is based on cookies, user ids or other identifiers. Over time, I expect more Prebid S2S adapters to be built which will help spur innovation and reduce disparities between client side and server-side solutions.
PubMatic offers a hybrid solution, called OpenWrap, that allows partners to work with both client-side and server-side integrations. With multi-format support of desktop, app, and video, publishers can manage their digital assets in a holistic solution. As the industry grows and shifts with innovations in inventory and ad tech, I look forward to seeing how common pain-points are addressed. To learn more about OpenWrap or our other solutions, contact us.