Had an issue with one site these past couple of weeks where a Google Analytics experiment was not collecting data even though Google Analytics was saying it was set up correctly.

One of the issues noted elsewhere was that the site set up for cross-domain tracking. For instance if the main site was www.topsemtips.com and the completion (sales) page was on secure.topsemtips.com then you have to set up analytics to know the two sites are interrelated using code similar to:

pageTracker._setDomainName(“topsemtips.com”);

Which some one else mentioned needed the additional code

Added above the experiment code. However this didn’t work. What I did find mentioned in Use Cross-Domain Tracking in an Experiment is that _setAllowHash needs an extra flag. Looking into this further that tag is deprecated from GA and is unnecessary – by removing the _setAllowHash everything finally started working.