Case Study: Deploying a whitelist on OpenRTB in 2019

Here is why it’s extremely difficult to get traction. But, if you do - CTR’s above 40% - can be achieved.

We all have them; clients/advertisers that just want to serve ads on a specific whitelist. And right they are. Many reasons exist to only serve ads on a specific whitelist. The biggest ones? Brand Safety, reaching a very specific audience and distrust in actual Brand Safety tools. The latter because Brand Safety tools – for example - claim they will protect your brand/offer from being served on low quality publishers. Any expert knows that – if you want volume (regarding your campaign) – such a statement is unrealistic.

Let’s take a step back. Because literally every hobby, every activity or every interest has a publisher dedicated to it. This creates interesting possibilities. For starters you would image it’s possible to serve just on publishers (sites/apps) that have your exact target-audience as an …. audience.


You are a horse food supplier. You want to serve ads in the about 30-70 publishers that are dedicated to horse-riding. Technically possible.

  • On a side note; serving ads ‘on/above’ the exact locations of actual horse stables is also a possibility.

Case Study: deploying a whitelist on OpenRTB anno 2019

Case Study: deploying a whitelist on OpenRTB anno 2019

You sell kite-surfing gear. You want to serve ads in the 25 to 45 publishers that are dedicated to kite-surfing. Technically possible. Not to mention publishers that report on wind conditions (like; Windfinder).

You are a driving instructor and want to serve ads in the 15 to 20 publishers that exist to help people learn driving. Technically possible.

You have a premium travel agency that specializes in high-end holidays in India. You want to serve ads in quality publishers that are about traveling. Also, you want to serve ads in quality news publishers (that have their own travel section. For example: and have a ‘rich’, travel minded audience. Here is where it gets interesting.

Our pleasant client Kamalan Travel wanted us to serve this ad:

Screenshot 2019-04-16 at 17.46.27.png

Within these publishers:

Der Zeit
New Yorker
The Atlantic
Robb Report
Travel & Leisure
Atlas Obscura 

Here is what happened:

  • We started bidding at $ 21 (Dynamic) CPM – knowing that there are likely others with the same idea and there will be others bidding at/on the same inventory (a bid of $ 21 is reasonably high).

    • No traction

  • We increased the bid to $ 44

    • No traction

  • Increased bid to $ 111

    • No traction

  • Increased bid to $ 241

    • No traction

  • Increased bit to $ 900

    • No traction

You know where this is going. In the end we got traction at a bid of $ 5002 and achieved a CPM of $ 3349. Logically we applied a daily spend cap – so the client doesn’t go bankrupt. Here is something amazing we witnessed; right now, after having the campaign live for about 40 days, we have a combined CTR of 45,6% (some days this peaked to 66,67%).


What does all this tell us?

Well, first of all – the competition regarding serving in ‘quality’ publishers is constant, persistent and heavy in 2019. Secondarily; - and this something many industry leaders know – if you want to actually win millions of impressions (which is nothing in terms of buying Programmatic) – there is no way around Ron Of Network (or; RON). Essentially you could say that all substantial campaigns are relying heavily on RON. In other words; it’s possible your brand/offer will be served within ‘shit’ publishers. So what do many consider ‘shit’ publishers:

  • Cleanmaster

  • Flashlight-Pro

  • Grindr (gay dating app)

As mentioned in a previous blogpost; these publishers are unbelievably popular when it comes down to sheer number of ad requests they fire. In other words; availability within these publishers is huge.

Rather interestingly, this client insisted on just serving within this specific whitelist. The CTR’s achieved are beyond believe. Campaign is ‘always-on’ and we will inform you of the progress (and; actual amount of inquires/conversions) of this campaign from time to time.


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