Here are some real discrepancies for two real campaigns that we’ve run recently, as submitted by one of our publishers. The publisher’s count is first, ours is second. The discrepancy is measured as a percentage of the publisher’s count.

Family Guy: 30,949 vs 20,936 (32.4 % discrepancy)
Ultimate Survival: 38,777 vs 26,159 (32.5% discrepancy)

Here’s what we have to say about this horrible disparity between the two counts.

• The discrepancy is consistent across the two campaigns
• It’s consistent with discrepancies we see on other publishers in the network, which are typically in the range 33-40%
• It’s consistent with discrepancies we’ve experienced in other jobs and companies when serving and tracking rich media campaigns
• Discrepancies arise because, ultimately, the publisher and the party serving the content are tracking different events (We don’t know what your counter counts, but we’re counting calls on a cache-busted 1×1 pixel that is called soon after the video stream is initiated)
• Publishers’ counts are generally higher than counts by the party serving the content because publishers are typically tracking an event that is earlier in the chain of events than the one being tracked by the party serving the content
• 15-20% reporting discrepancies are common on boring old banner campaigns. There are a number of reasons for this, including:
  • Browse-off: this is where visitors leave the page before a call is made to the party serving the content
  • Robots: advertising tracking systems typically filter out views from robots / spiders / crawlers
  • Javascript: advertising tracking systems that rely on Javascript will not count views where the visitor has Javascript disabled
• Discrepancies are much higher, often double (so 30-40%), for rich media campaigns, just because the serving and tracking is that much more complicated…often there are several calls to several servers before a call is made to the party who is serving the content

We don’t want to seem glib about what are, obviously, very large discrepancies, but we’ve worked with, at, and for ad serving companies for over 10 years. And the honest truth is that we just don’t blink when we see 40% discrepancies. It’s a total pain. It’s endemic in the industry. All the major publishers and ad agencies have to deal with this mess on a daily basis.

Ultimately, it’s just something you have to stick in the spread sheet and factor in when calculating the revenue efficiency of your various advertising partners.

Last updated on May 2, 2008 by Scott Button