I'm in the process of setting up VWO on my website and will be using an eVar to push he data to. I'm not 100% sure what the 'Expire After' setting should be in Adobe Analytics. Do I want the data to expire after the visit or to never expire? VWO uses a cookie to make sure that when a user sees a test, when they return they will see the same version of the test. This leads me to believe I should set the 'Expire After' to 'Never'.
However, while doing some testing, I noticed this scenario - I viewed the test to ensure the data was coming in ok, then bought a product after viewing the test. So far so good. The following day I bought several more products without viewing the test but because the eVar still had the original test value associated with it, those conversion were also given credit to the eVar. This is what I'd expect but as the test played no part in conversions on the second day, should it really be getting the credit?
Most of the A/B Testing tools behaves the same way as VWO, even Adobe Test & Target. That is the reason the results will not match the Adobe Analytics Data often.
Answer or comment to your question is, Based on Requirement.
If you set the expiration of eVar to Visit in Adobe Analytics, credit will not be assigned to the success event happened after the visit. But this is not the case for VWO and the result in VWO will still show the credit till the cookie expiration.
So it is you to decide the proceedings. Both the logical in its own way!
You can always set the eVar each time they view the experience, then expire the eVar on visit. That way, if they don't see the experience on the second visit, the eVar won't get credit. If they do view the experience, the eVar is set again and can be properly attributed.