Bid Filtering

When you use Authorized Buyers to respond to bid requests, it's important that your bid response makes it to the auction. Some bids are rejected before they can enter the auction because of bid response filtering.

Background

Every bid that you submit undergoes a screening process before it can enter the live auction. During this process, your bid may be rejected for reasons like publisher exclusions, or having an invalid bid response. Among other things, we check for malformed URLs, ads that fall into a category the publisher has blocked, or incompatible elements in a bid response.

Figure 1 is a conceptualization of the process a bid goes through, including bid response filtering, to make it into the auction and win:

A visual depiction of the bid response filtering process.
Figure 1:Bid processing.

Main bid response filters

As the bid response progresses through the process illustrated above, it might be filtered out by Google, the publisher, or during the actual auction for many different reasons. Each of the main bid response filtering mechanisms is discussed in detail below.

Google-filtered

First, Google reviews the bid response to determine if both the creative and the bid are compliant with Google policies and standards. Here are the most common reasons your bid response will be filtered out by Google:

Disapproved ad
The ad in the bid response was disapproved for one of several reasons. In order to determine the exact reason for which your ad was disapproved, review the creatives resource.
Max CPM is 0 or negative
The bid (BidResponse.seatbid.bid.price) was 0 or a negative value. Change the bid to a positive value. If you are not interested in bidding for a particular bid request, be sure to return an empty bid response with the processing time set, not just an empty (0 bytes) response.
Max CPM is too high
The bid (BidResponse.seatbid.bid.price) set in the bid response was higher than the limit imposed by Authorized Buyers to protect itself and its partners from bugs and misconfigurations. The limit is 5000 US dollars CPM ($5 per impression). Change the bid to be $5000 CPM or lower—for example, if you are bidding in US dollars, the value of price must be 5000 or lower. Contact your Technical Account Manager if you want to be able to pay more than this limit.
Click-through URL or advertiser domain is too short
The URL specified for BidResponse.seatbid.bid.adomain or BidResponse.seatbid.bid.ext.clickurl is less than eleven characters long. For example, the URL http://a.b would be too short. Verify that the URL specified is more than eleven characters long.
Click-through URL or advertiser domain is unparsable
The URL specified for BidResponse.seatbid.bid.adomain or BidResponse.seatbid.bid.ext.clickurl is malformed and cannot be parsed. For example, http://myad won't work since the domain name has to include at least one period.
Invalid bid response
The bid response isn't parseable, or is in an invalid state. One example of an invalid state would be if BidResponse.seatbid.bid.crid were left unset. We recommend reviewing the OpenRTB guide and the response guide to learn more about creating valid bid responses.
Poor landing page quality
The landing page was disapproved by Google. Review the landing page of the ad to make sure that the website provides a good user experience as measured by:
Relevant and original content
The site needs to be relevant and have original content; it should not copy text from another site.
Transparency
The site needs to be very clear on what the business model is and how any information gathered by the site will be used.
Ease of navigation
The site should be easy to navigate and it should not be intrusive to users.
Account exceeds snippet quota
There is a limit on how many creatives may be active over a 30 day period. A creative is considered active if it had been inserted through the API or had been bid with during this period. New creatives, or creatives that had not been inserted or bid within the preceding 30 days, will be filtered if the account exhausts this quota. You may bid with new creatives once the number of creatives that have been active over the preceding 30 days drops below your quota. The limit and the number of active creatives may be obtained through the RTB Protocol. Under certain circumstances, Google may increase this limit. Google will base quota provisioning primarily on the account's average daily spend. Accounts should attempt to maintain usage within 1.5 creatives per dollar of daily spend. Contact your technical account manager for details.

Publisher-filtered

Once the bid makes it through Google's review, it is reviewed again to ensure it adheres to the publisher's requirements. For each piece of ad inventory, the publisher can add exclusions. Here is a list of the main reasons a bid could be filtered out by a publisher:

Sensitive category URL excluded
The click-through URL you specified with BidResponse.seatbid.bid.adomain or BidResponse.seatbid.bid.ext.clickurlwas either detected or declared to have content that fits into a sensitive category that was excluded by the publisher for this request. In order to determine the sensitive categories for each publisher, you can review the blocked advertiser categories found in BidRequest.bcat. The Real-time Bidding API creatives resource will show the sensitive categories associated with your creative's click-through URL.
Product category URL excluded
The click-through URL you specified with BidResponse.seatbid.bid.adomain or BidResponse.seatbid.bid.ext.clickurlwas either detected or declared with a product category that has been excluded by the publisher for this request. In order to determine the product categories prohibited by each publisher, review the blocked advertiser categories found in BidRequest.bcat. The Real-time Bidding API creatives resource will show the product categories associated with your creative's click-through URL.
Declared attributes excluded

The bid response has declared attributes which were excluded by the publisher's ad slot in the bid request. In order to determine the excluded attributes, you will need to review the following fields in the bid request:

  • BidRequest.imp.banner.battr
  • BidRequest.imp.video.battr
  • BidRequest.imp.audio.battr
  • BidRequest.imp.native.battr

Auction-filtered

After the bid response passes both the Google and publisher reviews, it makes its way to the auction. However, the bid may not enter the auction if it was lower than the publisher's required min CPM. If this is the case, the message "Max CPM is lower than the publisher's min CPM" will be returned:

Bid amount is lower than the publisher's bid floor
The bid response contained a BidResponse.seatbid.bid.price value that was lower than the publisher's configured minimum. This will occur if your bidder places bids with a price less than BidRequest.imp.bidfloor when converted to the currency used in the bid.

Summary

You can review the following to reduce your bid filtering:

  1. Disapproved creatives.
  2. Excluded dimensions in the publisher settings report
  3. The publisher's min CPM requirement in the bid request

Reduce bid filtering

The following can reduce the amount of your bids that are filtered:

Filtering assist

Filtering Assist predicts creatives that are likely to be filtered so you can avoid choosing them in your bid response. See the Filtering Assist guide for details.

Multi-Bidding

Submitting more bids may increase your chance of winning in the ad auction. We recommend submitting multiple bid responses for each bid request you get.

Creatives API

You can use the Creatives API to get creatives approved prior to bidding, and to determine which of your creatives meet publisher settings. Publisher settings are included in the bid request, and you can use them to choose creatives to include in your bids.

Creatives that comply with publisher settings aren't filtered by publisher blocks and have a higher chance of entering auctions.

Publisher settings are in the following signals of the bid request:

OpenRTB

  • BidRequest.wlang
  • BidRequest.bcat
  • BidRequest.imp.ext.allowed_vendor_type
  • BidRequest.imp.ext.allowed_restricted_category
  • BidRequest.imp.{banner,video,native,audio}.battr

Google RTB protocol (deprecated)

  • BidRequest.adslot.excluded_attribute
  • BidRequest.adslot.allowed_vendor_type
  • BidRequest.adslot.allowed_languages
  • BidRequest.adslot.excluded_sensitive_category
  • BidRequest.adslot.allowed_restricted_category
  • BidRequest.adslot.excluded_product_category

Filtered fields

Here's how some of the filtered fields map from the Creatives API to the RTB protocols:

Creatives API CreativeServingDecision Authorized Buyers protocol OpenRTB protocol
detected_attributes excluded_attribute Native.battr, Audio.battr, Video.battr, Banner.attr
detected_vendor_ids allowed_vendor_type ImpExtension.allowed_vendor_type
detected_languages allowed_languages wlang
detected_sensitive_category excluded_sensitive_category bcat
detected_product_category excluded_product_category bcat
restricted_categories allowed_restricted_category ImpExtension.allowed_restricted_category
detected_domains publisher_settings_list_id, adslot.publisher_settings_list_id ImpExtension.publisher_settings_list_id
detected_click_through_urls publisher_settings_list_id, adslot.publisher_settings_list_id ImpExtension.publisher_settings_list_id

See the Creatives API guide for more details.

If you have questions, or want to get a report for bid response filtering issues, reach out to your Authorized Buyers account team.