When using Ad Exchange, one of the most important factors is ensuring that your bid response is participating in the auction. If the bid response makes it to the auction, it has a better chance at improving win rate: percent of impressions won out of all bids submitted. However, it’s possible that some of your bids may not be entering the auction due to bid response filtering.
We’ll review bid response filters later in this blog entry: what they are, and how to ensure your bid responses are not filtered out. But before we dive in, let’s define bid response filtering.
What is bid response filtering?
Each real-time bid that is submitted to Ad Exchange undergoes a screening process before it can enter the live auction. During this process, your bid may be filtered due to publisher exclusions or incorrect use of the RTB BidResponse protocol. Among other things, we check for malformed URLs, ads that fall into a category the publisher has blocked, or incompatible elements in the bid response (e.g., a buyer who has declared an expandable ads technology vendor, but who has not actually trafficked an expandable ad).
Here is a basic visual representation of the process a bid goes through, including bid response filtering, to make it into the auction and win:
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 are discussed in detail below.
Google Filtered: First, Google will review the bid response to determine if both the ad creative and bid are compliant with Google’s policies and standards. Here are the most common reasons your bid response will be filtered out by Google:
Note: The snippet status report will also show ads that have not been checked and are filtered.
And as a proactive measure, the creative REST API provides methods for submitting a creative for verification, for checking the status of a creative that you have submitted, and for retrieving a list of all your active creatives before bidding on the creative ad.
Max CPM is 0 or negative means the bid (max_cpm_micros) set in the bid response 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.
Click through URL is too short means for bid responses where html_snippet is set, the click_through_url is less than eleven characters. For example, the URL http://a.b would be too short. Verify that your click_through_url is more than eleven characters.
Click through URL is unparsable means the click_through_url in the bid response is malformed and cannot be parsed. For example, 'http://myad' will not work, since the domain name has to include at least one '.' (period).
Incorrect use of bid response protocol means that there is an improper setting in the BidResponse. In order to determine the proper protocol, review Building the Response and the realtime-bidding.proto.txt file. The realtime-bidding.proto.txt file defines the appropriate settings that should be included in the BidResponse. Examples of incorrect protocol use include: buyer_creative_id not set in the BidResponse or setting both the html_snippet and video_url fields in the BidResponse (only one should be set).
Poor landing page quality means that the landing page was disapproved by Google. Review the landing page of the ad to make sure 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 what the information will be used for.
- Ease of navigation: The site should be easy to navigate and it should not be intrusive to users.
Product category URL excluded means that the click_through_url in your bid response was 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 excluded_product_category field in the bid request and the publisher settings report. The publisher-settings-proto.txt file lists the categories that are excluded. Your snippet status report will show the product category with which your snippet’s click_through_url was classified by Google.
Declared vendors excluded means the bid response has declared a vendor_type which has been excluded by the publisher’s ad slot in the bid request. In order to determine the vendor types allowed by each publisher, review the allowed_vendor_type field in the bid request and the publisher settings report. The publisher-settings-proto.txt file will show you the allowed vendors.
Declared attributes excluded means the bid response has declared attributes which were excluded by the publisher’s ad slot in the bid request. In order to determine the allowed_vendor_type per publisher, you will need to review the excluded_attribute field in the bid request and the publisher settings report. The publisher-settings-proto.txt file will list the excluded attributes.
Remember, each bid response that is filtered out is a valuable impression you’ve missed out on. Therefore, always review the following:
Posted by the Ad Exchange Team