Switch will look into discrepancies above “10%”, however before we do so please scan the below document as it contains both the guidelines we use to identify if we will investigate this for you, and also provide a list of common discrepancy causes.
Each Adserver has its own counting methodologies. It’s worth asking the advertiser how and when they log an impression as some publishers can count impressions at the time the ad request is sent, whilst other advertisers can count an impression when the creative/ad is delivered.
Switch count both, we send out a “request” which is where the ad tag loads on the page and requests an ad from our Adserver. We then log an “impression” when the lg.php call is fired, which is a confirmation that Switch has chosen an advertiser and their creative has rendered on the page.
Latency, Page Views and High Bounce rates:
Latency can occur between a 3rd party a creative and Switch and lead to discrepancies. For example, if the 3rd party has supplied a particular heavy creative/rich media targeted to mobile. The user has more than likely navigated away from the page before the advert has finished rendering especially if they are using mobile data.
If your site has a high bounce rate and low page views this can lead to discrepancies between request vs impression discrepancy and with other Adservers. This could be down to if the user has low bandwidth they may have navigated away from the page before the ad has rendered. This can also happen if the user is navigating quickly through the content of the site. Quality of traffic can also impact page views/bounce rate, this is explained further down.
To improve latency on load ensure you are using our latest asynchronous ad tags, as these are loaded independently to the webpage. Additionally, if your webpage has a substantial amount of elements on the webpage this can also delay the load of our tags.
Adservers all have different methods for filtering impressions which include filtering spammers, bots, spiders and other automated or non-representative web traffic.
Switch performs both internal and external traffic quality checks. If your site fails these tests then you will be unlinked from Switch’s demand partners without further explanation.
Volume of traffic to the site:
Low volumes can inflate the percentage of the discrepancy. It's recommended to send through at least a few thousand impressions to gain a more appropriate reflection.
Are there any frequency capping/delivery limitations applied on the 3rs parties end?
If so are these mirrored within Switch UI? If they are not we will see discrepancies between both parties as well as the potential of blank ads displaying if the relevant restrictions have not been applied within Switch.
Have you modified our Ad tag?
If so then we will not look into the discrepancy. The Switch tag is designed to be used exactly as pulled from the Adserver.
Are our macros implemented correctly in the tags?
Our tags have a cachebuster inbuilt as a result there is no need to implement a 3rd party’s cachebuster. However for 3rd party’s tags trafficked within Switch please be sure to implement the relevant click macros. Be it a click macro to ensure we are tracking clicks alongside the tag provider, or our cachebuster to ensure we are not serving the cached creative.