Header Bidding Implementations in the Wild


Example Publisher: HotAir.com

Domain: http://ox-d.tmn.servedbyopenx.com/ and http://ox-d.townhallmedia.servedbyopenx.com

Keyvalue: ox or ox combined with size, for example, ox728x90

OpenX has a more detailed response than many other header bidders, but it’s very nicely organized and easy to understand.  Similar to Casale, OpenX passes more details about the creative in particular, as well as brand / advertiser parameters which I imagine could be very helpful to log for billing or reporting purposes downstream.  In terms of variables, ‘pub_rev’ is the parameter they use in their own response, and as you can see from the second image, publishers then typically pass that value into their ad server using the ‘ox’ or ‘ox[size]’ key.

OpenX Header Bidding

OpenX Header Bidding


Example Publisher: Topix.com

Domain: http://gads.pubmatic.com

Keyvalue: bid

PubMatic was an early player in header bidding, and they still have one of the easiest implementations to understand.  They return a position value, rate, creative ID, and that’s basically it, letting the publisher pass the rate only into their ad call.  Simple and elegant.

PubMatic Header Bidding

PubMatic Header Bidding


Example Publisher: HotAir.com

Domain: http://anvil.rubiconproject.com/a/api or http://optimized-by.rubiconproject.com/a/api/fastlane

Keyvalue: rp_cpm

For some reason, Rubicon seems to do header bidding differently than other companies.  For one, they appear to require a separate call per ad slot on the page, vs. an array of sizes like every one else can take.  They also don’t always appear to pass the price as a key-value to the ad server, even though they always seem to return it in their response, rather they sometimes abstract the rate into a handful of ‘tier’ values, probably to make it simpler for Ad Ops to traffic the necessary line items in DFP.  My sense is they’ll reconsider that if they aren’t in the process of migrating folks over to an exact value solution given virtually every other bidder now passes an exact value to the ad server.  I’ve also seen them change their approach a few times in the past year, so my sense is whatever I document here won’t be their solution in a few months, as it seems like they are still tweaking it. In addition to HotAir, the Tribune media companies have spoken publicly about using Rubicon’s header bidding technology on their large network of premium sites.

Rubicon Header Bidding

Rubicon Header Bidding


  1. Rubicon is working on a specific actual value solution called project fast lane but it is doing so begrudgingly. Rubicon believes correctly (however, almost no publishers manager their stacks completely correctly to take advantage.) That the way to value an auction/ yield management is in terms of scarcity. Exact price doesn’t matter from this perspective of yield management. If they return a “yes” in a certain tier it means that impression is a high enough value and rare enough in Rubicon it should get priority unless AdX beats a specific floor. This methodology when done correctly distributes impressions to the highest possible value across the entire campaign.

  2. Interesting color, Dave – thanks for the comment. I think I’d probably need more detail to really take an opinion on Rubicon’s described approach, although I’m not sure it makes sense at face value that exact price doesn’t matter as long as the relative price is higher. For one, I think that makes it pretty difficult to audit how good a job Rubicon’s system would do at calling higher / lower than AdX, and second, I think it makes log level data a lot more difficult to work with. That said, Rubicon has a smart team and I’m sure there’s more than meets the eye here – hopefully they’ll release more details on their unique take with header bidding.

  3. For additionally clarity I forgot to add that their solution was designed to compete with a publisher’s direct/ guaranteed demand and allow for “price less auctions”, the idea being if direct is pacing, a scarce impression should serve. With that in mind, Rubicon actively promotes that if you use their header solution no other header tags should be allowed. The argument being fixed header bids like Criteo generally fill say 5-10% of impressions typically make the market (as the 2nd price) over 50% of the time in an auction environment and that long term fragmenting demand and turing exchanges into bidders will hurt CPMs. I agree in the case of fixed bidders like Criteo, but not for other similar exchanges to Rubicon.

  4. Hi Alex,

    Yes, Space.com has a working example – just open your developer tools and search for ‘prebid.js’ on the Network tab.

    Hope that helps!

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