Rich-text Reply

"Visitor is returned" + "New Visitor" doesn't match "All visitor" in result pages

Tammy 01-13-15

"Visitor is returned" + "New Visitor" doesn't match "All visitor" in result pages



I just started using and learning Optimizely very recently.  I am totally new.   :-)

Sorry if I ask you something weird from now!


The thing I would like to know is the detailed condition and specification for capturing "All Visitor", "Visitor is returned" and "New Visitor" for Optimizely.

I know Optimizely is using 10 years Cookie for figure out unique user - but I would like to know more detailed infomation especially about how you guys separate "Visitor is returned" and "New User".


The reason why I'm asking this is because I found ["Visitor is returned" + "New Visitor"]  doesn't match "All visitor" in my test result



For instance, according my test, I took a look at the count after filtering each visitor type.


All visitor : 3,720

Visitor is returned : 2,799

New visitor : 1,102


I am simply wondering maybe there is the duplicatied count or missing count between new visitor and returned visitor.... but it's just a wondering, I would like to make this clear.

If you have any specification document to help me to understand how you guys specify each visitor type, it'll be deeply appreciated.


Thank you,






Level 6

Brian_Abad 01-13-15

Re: "Visitor is returned" + "New Visitor" doesn't match "All visitor"

Hey @Tammy ,


Welcome to Optimizely and the Optiverse Community! Really glad to have you on board for all your testing needs!


When a user first lands on your domain with the Optimizely snippet on the page, we drop a cookie onto their browser that holds a unique user ID. If the user does NOT have this user ID value when they initially land on your page, they are counted as a new visitor. If they land on your page and HAVE the user ID, they are counted as a returning visitor.


When interpreting results, a user may be counted as both a new and a returning visitor. For instance, if when entering your experiment, it is the first time they land on a page with your Project's Optimizely snippet, they will be counted as a new visitor. If this same user returns, they will be counted as a returning visitor. However, within the Results page for your experiment they will only count as 1 unique visitor. Filtering for both new and returning visitors will return a value of 1 for both filters, but the overall unique visitor count is still at 1. So the sum of the 2 filters should not equal the overall unique visitor count.


The key here is that they do not need to have been bucketed into the experiment, but rather have landed on a page that contains your project's Optimizely snippet. So if you have the snippet on and but the experiment is only running on -- a user can land on, receive the user ID value, exit their browser, then come back to where your experiment is running, and they will be counted as a return visitor.


More on new and returning visitors can be found in our knowledge base article here:

Brian Abad
Manager, Technical Support
Customer Success
Tammy 01-14-15

Re: "Visitor is returned" + "New Visitor" doesn't match "All visitor"

Thank you @Brian_Abad!


That is exactlly what I wanted to know!

Thank you for helping me!



Level 6