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Reed Smith Ad Bites #7: ANA Programmatic Media Supply Chain Transparency Study

Reed Smith formed part of the core team drafting the seminal Association of National Advertisers (ANA) Programmatic Media Supply Chain Transparency Study. Our “RS Ad Bites” break down each of the findings and deliver the key considerations for marketers to think about to protect the bottom line and increase efficiency when dealing with agencies and vendor partners in connection with programmatic media buying. 

Below is the seventh in our series. The full report can be found at

Optimizing the mix between open marketplace and private marketplace buys

Marketers should aim to optimize their open marketplace (OMP) and private marketplace (PMP) strategy to allow them to reach their desired target audience while maximizing ad spend efficiency. 

In PMP buys, ad inventory is made available programmatically on an exchange to select advertisers or buyers. Conversely, on an OMP, anyone can buy the ad inventory from the seller. 

The ANA found that the majority of programmatic ad spend (59%) is directed to OMPs. A key advantage of OMP buying is that OMPs provide cost-effective access to a broad audience as they offer a wide range of ad inventory. However, OMP buys typically result in a higher quantity of low quality “made for advertising” (MFA) impressions than PMP buys. For example, the ANA found that OMP buys in its study had an average of 26.8% MFA impressions, while PMP buys with over 500 domains had an average of 19.8% MFA impressions and PMP buys with 11 to 500 domains had an average of just 1.3% MFA impressions. 

PMP buys can provide advertisers with greater control over audience, publishers, placements, and pricing and greater access to unique creative units such as rich media ad units, which include features like video, audio, or other elements that encourage viewers to interact and engage with the content. For these reasons, PMP buys are often priced as premium offerings on the basis that they provide higher quality inventory and better viewability.

However, PMP buys vary in both scope and quality. For example, PMP buys may involve the purchase of ad inventory on a small number of domains (for example, just one to 10 websites) across a single portfolio. Equally, a PMP buy could involve the purchase of a curated PMP package for ad inventory on up to 500 domains, which may all share a focus on a particular type of ad product or content. 

The ANA’s study shows that PMP buys that cover a high quantity of domains (500+) are not always the best choice for advertisers looking to obtain quality inventory and ad impressions. As noted by Tom Triscari, PMPs sometimes mix high quality inventory with low quality inventory (including MFA sites) in order to maintain an overall low cost per thousand impressions. The ANA study shows that for PMP buys that cover over 500 domains, there is a high prevalence of low-quality MFA impressions (19.8% MFA impressions on average, as mentioned above). 

Playbook and key considerations

  1. Adopt a data-driven approach to PMP buys: To help to ensure that PMP buys represent good value for money, use log level data to assess the costs and quality of impressions that you gain from PMP buys. With this information, you can recalibrate PMP buy pricing to reflect the results of these assessments or adjust your PMP/OMP strategy to allocate more budget to OMP buys. With proper checks, controls, and optimizations in place, OMP inventory can drive comparable quality at a lower cost. 

Alternatively, if log level data is not available, contract for domain analysis reports to help you to assess the quality of inventory on offer. These reports should show (at a minimum) the seller or supply-side platform for each domain listing, the ad types on each domain listing (for example, display, video, CTV), and the ad impressions for each domain. 

2. Continuous monitoring and adjustment: Work with media specialists or outside counsel to ensure that your agency agreements give you the flexibility to review and adjust your OMP and PMP strategy and ad spend allocation based on the data. 


media buying, ad law, ana, programmatic media, entertainment & media