Difference of 10% between various analytics tools is natural, however if there is a huge gap, this mismatch certainly has to be looked at and resolved.
The most common reasons why there could be a difference between GA and IO numbers:
- IO code wasn't added to the mobile version of the website
- IO code is missing on certain sections of the website, so we don't get data from the whole site
- there are AMP pages\Instant articles that don't have IO code
- there are two GA codes that collect data to the same account, resulting in higher overall numbers
- some features could be tracked differently: endless scroll or galleries tracking are the most frequent cases
Please keep in mind that in general Google Analytics is a solution that is set up differently by/for every account/publisher. Therefore, there are various unique cases that could also be the reasons that cause the difference in numbers between IO and GA.
The quickest and the most efficient way for our developers to solve possible discrepancies is to get access to your GA account. You understand that we have access to you data via our service anyway, we would simply be checking the way reports are being set up at your GA account now.