iOS SEM Conversions Severely Undercounted


abacusADOTAS – Sounds like it’s time for search marketers to get their hands out of the third-party cookie jar. According to Marin Software, SEM advertisers using redirect-based tracking systems are having their conversions undercounted by 38% on average.

That figure gets far worse on iOS devices — Marin discovered that paid search conversions from Apple’s iOS devices could be undercounted by as much as 80%, compared to 51% for Mac Safari users and 38% for the average Windows user. While perceived conversions on the iOS platform were 56% lower than those on Windows, actual conversions were 23% higher.


The software company notes that primary iOS browser Safari blocks cookies by default, and changing this setting on the iPhone or iPad is a multistep process that seems to encourage users to block third-party cookies. For Marin’s client base, 5% of traffic came from iOS devices, a figure that’s bound to grow if Apple mobile device sales are to be trusted.

Marin’s advice? “Advertisers should look to actively transition away from using third-party redirects wherever possible…. If transitioning to a first-party cookie solution is not an option, advertisers should adjust their metrics to account for unattributed conversions that result from third-party cookie blocking.”


  1. Joe Malley, April 7th, 2011 at 10:35 am ET:
    Is the “problem” the technology that circumvents the iOS default settings and user’s security preferences, or the use of an “invisible cookie” from a third party domain, coded as a first party domain, a domain other than the domain of the original page requested by the user?


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