Unique Visitor has big gaps comparing to Approximate Event Visitor GUID

[Royyyyy]

Hi there,

I realize the metric Unique Visitor is often much higher than if I create a manual approximate distinct metric on event visitor guid (ECID). 

What's some possible reasons behind the gap?

Thanks!

  

[Jennifer_Dungan · Accepted solution]

Is it possible your ECID is failing to set all the time? Maybe you have visitors that are being identified still by the s_id, or f_id, or maybe you have AMP_id... do you have any no_script tracking in place where no id is being set at all?

[Royyyyy]

I see, yea I'll check that thanks!