With the introduction of Header bidding programmatic advertising industry has completely disrupted. Its still relatively new to the world and all publishers are trying to find out the sweet spot between maximized revenue and good user experience. Publishers have seen the improved yield as a result of Header bidding. Cached bid is a considered as one of the optimization techniques by various SSP's. On record biggest SSP's like PubMatic, OpenX & Rubicon etc say that they do not use this technique at all. Bid caching reuses a bid you have submitted in one auction for future auctions. This benefits an exchange as it increases the chance that they will win multiple auctions in a particular session. It also increase publishers yield.
As it is considered as black hat technique. But no wonder any thing is possible in the ever changing Adtech world. And exchanges might be doing it. But are publishers aware of this? Are publishers being paid higher CPM's for bids won by SSP's using this technique. I'm not aware of any publisher being informed about this tactic. The expectation of partners is that they seek explicit approval before making a fundamental change to decisioning in the supply chain. I am not sure if any legitimate SSP doing this. Also its quite difficult to deal with multiple bid responses (at scale) within 200 milliseconds without caching a load of additional bids that you may (or may not!) want to add into the auction would be madness. Also I think DSP's know what auction they are bidding for. Also I think most auctions have unique auction ID's. So buyer can find this easily and highlight it to court.
Cached bid is not considered good for buyers as they might end up paying a lot more money. It might cause brand safety issue. Quality related to viewability etc might pop up. Performance of buyers will be low on these web pages. Hence an advertiser might not consider a particular publisher for all of their future campaigns.
I am calling it a black a black hat technique but it may be white hat for a lot of publishers and exchanges like Index Exchange. Index Exchange has seen sky rocketing performance since launch of Header bidding. It was gaming the
auction. All my colleagues on the publisher side were asking how come Index is offering such higher CPM's. Index uses to be a small ad network know as Casale Media. It also become a preferred partner for Google's Header Bidding product called as Google EBDA. Now it has disclosed in it own blog post about
bid caching
Bid Caching is a threat to the industry. Its leads to
Transparency
Real Time promise
Pre bid optimisation and brand safety filters
Frequency cap
