Last year, we introduced the Ad Exchange Real-Time Bidding Optimization Series on the developer's blog with our first post on post-filtered bids.

Today, we’ll drill down into one of the filtering reasons: Auction filtered.

We’ll revisit the definition of auction filtered bids, review the main reasons for being filtered from the auction, and the steps you can take to ensure your ads will not be filtered.

Auction Filtered: After the bid response passes the Google and publisher checks, it makes its way to the auction. However, the bid may not win the auction due to one of the following:

1. Outbid in auction
2. Bid was below the minimum threshold
3. Not allowed in private auction

1. Outbid in auction means that your bid was lower than a competitor’s bid and since AdX uses a second-price auction model, the highest bid wins the auction and pays the price of the second highest bid. One way to make sure you are bidding at a competitive price is to implement the new RTB feature for AdX, Real-time Feedback. The feature will give you feedback on auction results in near real-time, including (1) why your bid was filtered (e.g. disapproved ads, product/sensitive category exclusion, outbid in auction, etc.) and (2) what the winning bid price was (if you lost in the previous auction). We include this information in subsequent bid requests sent to your bidder. You can use this information to improve the efficacy of your own bidding by reducing the number of times you are outbid. The creative_status_code field in the proto buffer will reveal the filtering reason. For example, the creative_status_code field may be 79, meaning you were ‘outbid in auction’, whereas 80 and 81 mean your ‘bid was below the minimum threshold’ and ‘not allowed in private auction’ respectively. You can review a complete list of filtering reasons in the creative-status-codes.txt dictionary file.

2. Bid was below the minimum threshold means that your Max CPM (max_cpm_micros in your BidResponse) was lower than the publisher’s min CPM. Specifically, the bid response contained a max_cpm_micros value that was less than the publisher’s minimum_cpm_micros value. Ensure that your bidder understands the minimum_cpm_micros required by the publisher per bid request and bid at or higher than this price if you are interested in the impression, or submit an empty bid if you are not interested in the impression. The minimum_cpm_micros value is listed in the AdSlot section of the bid request. You can review more details in the realtime-bidding-proto.txt file.

3. Not allowed in private auction means that your bid is being filtered for a preferred deal or private auction impression that you were not allowed in. Using the Preferred Deals UI, view Open Offers and consider negotiating your own deal or private auction with publishers of interest.

New! RTB Dashboard is a tool designed to bring greater transparency to you, as a buyer, and help you refine your bidder to produce more efficient bidding and better results for your campaigns. With RTB Dashboard, you have the ability to review the “RTB insights” section which helps you understand which bids are being filtered out and why:

So, what can you do with the information available in ‘Insights’? Two of the most common auction loss reasons and solutions are:

  • Outplaced - use real time feedback to analyze which impressions you get outbid on and increase your bid intelligently. The bid request contains the second price cpm in micros of your account currency if your bid won the auction, or the winning bid that must be exceeded to win the auction if your ad did not win. This is only set if your bid participated in the auction.
  • Below CPM - Inspect the minimum_cpm_micros field in the bid request and ensure you’re bidding at or above this amount.

For both auction loss reasons you may want to find out more. Under the ‘Action’ column a ‘Details’ link allows you to view the auction loss count aggregated by either publisher domain or your creative ID for the specific auction loss reason.

Have questions or feedback? Reach out to your Ad Exchange account team.