Why do we have the same visitor id for multiple sessions (web-traffic from different countries)?

[Shaista_L]

The Adobe Visitor Id is not unique if its a combination of post_visid_high and post_visid_low then it should be unique. Can you give me an example explaining the generation of visitor id using combination of post_visid_high and post_visid_low, I see in the data the visitor id is alpha numeric ,Is there a conversion?

Also , If a person gets assigned a Adobe Visitor Id  and comes back (after few days) to visit the same page/website will he/she be assigned the same Adobe visitor Id (assuming they didn't delete the cookies). I am having issues where we cannot identify customers ,because the post_evar value is not always captured in DatawareHouse. What could be the possible reason's for an post evar value to be not captured which makes the customer unidentifiable ?

[Ankit_Sharma_]

shaista.l​ There is a conversion happened on visitor Id depends on what type of visitor identification is used, the visitor can be identified either using s_vi (legacy visitors identification), mid (experience cloud ID service), FID(fall back) more details listed here:

Identifying Unique Visitors

The s_vi cookie is hexadecimal value when initially send to data collection server and it converts to decimal value and post in visid_high and visid_low values. same with the FID.

There is no conversion for mid value. if they don;t delete the cookie yes the cookie value will be same providing the cookies are not blocked by the browsers, evar is not used to identify the visitors, you might be sending the visitorID value in an eVar, I think that's why you are trying to compare it, but it will make more sense when you pull the data feed and look for the values in column post_visid_type to check what identifier is used to identify the visitors.

Hit Source Lookup

Hope this helps.

[sanmeetw1519854]

Hi Shaista,

If you are using the data warehouse, then it contains 2 standard out of box variables to record the visitor Ids. It does not require any custom implementation. The name of the variables are visitor id and experience cloud visitor Id. You can use these instead of visid_low/high from the clickstream feeds. This will also not require reliance on any custom eVar setup. It is a good practice to record the visitor Id in custom eVar though as the variables i mentioned earlier for DataWarehouse are not available in Report & Analytics/Workspace.

If the implementation has been done properly then in the same browser without the visitor deliberately deleting the cookies, there should not be allotment of different IDs. The only scenario where this would be possible is if the implementation involves some kind of custom cookie setup for IDs with encrypted value of visitor login or registration.

Let me know if you have any more questions.

Best,

Sanmeet Singh Walia

[Shaista_L]

Thank you so much sanmeetwalia, Basically the set up we have for Adobe is using visitor Id NOT the cloud experience id. For better explanation purpose. The post_visid_type we use is '3' .  Refer below to the look up for post_visid_type.

post_visid_type

1=IP&UA fallback (cookies were rejected by browser)

2=Wireless (HTTP Mobile Subscriber Header identified as mobile carrier)

3=Adobe (server generated, stored in s_vi on client) Default method.

4=Fallback cookie (new fallback ID, JavaScript generated, stored in s_fid on client, added in H25.3)

And the Adobe Visitor Id we pass to an evar value. The problem is multiple sessions have the same Adobe Visitor Id.

For example

visid_high	visid_low	AdobeVisitorId
3301383017962990000	6917530153461280000	1f5aacf448ed89563oo555605eccc8d2
3341281681447380000	6917532334230600000	1f5aacf448ed89563oo555605eccc8d3
3336257190330840000	4611705363496980000	1f5aacf448ed89563oo555605eccc8d4

All these above sessions are from different users from different geo locations visiting at different times and I also checked if there are visiting the same page which is also not the case, Do you think there is a problem with  the set up where these multiple persons get assigned the same AdobeVisitorId value . I have also checked various columns that basically distinguish that all these visits are unique but I don't understand why they get assigned the same Adobe Visitor Id.

[Ankit_Sharma_]

Hi Shaista,

if I am reading this right you are capturing these values in an eVar from the s_vi which is set on the tracking server, i noticed that all three are different, notice how we have 2, 3 and 4 and the end of each values, i am interested in knowing how you are passing these values in that eVar..

[Shaista_L]

Hi ankits28281247​. Thank you for  taking time to answer this question. Appreciate all your help.

Sorry my mistake I was making up dummy data for example purposes but all the fields for the Adobe visitor Id are basically the same ,for instance  = 1f5aacf448ed89563oo555605eccc8d3 . I wasn't part of the setup years ago, but now we are trying to make sense of the existing and future data for our analytic needs.  I think the way it is setup is out of box variable is being passed to an evar is my conclusion.I might be wrong. My end goal is to identify unique visitor, which is impossible with all the discrepancies with the Adobe ID. Could you shed some light on the tracking server. I am not sure what that means.

[Ankit_Sharma_]

Tracking server is the location which is required to store the image request and cookies for the data collection for reporting purpose.

s_vi based on which visitor is identified is always set on the tracking server domain: Correctly populate the trackingServer and trackingServerSecure variable

it seems like to be the case to me but I think in order to validate if the implementation is right, you have two way:

Data warehouse: you can pull a data warehouse report with VisitorID and eVar columns to see if you are seeing different eVar value for the same visitor ID, if that be the case you might want to review your implementation and check with the developers how they are setting eVar.

Data Feed: it's the data which is raw format and stored at adobe server exactly in the form of how it's been sent from the website and you can setup a data feed and review the data to validate the same thing: here is the document which helps how you can leverage the data feed information and setup for your use: Analytics Data Feed

[Shaista_L]

I am using the data feed , basically we get a raw file with the data feed for previous day that has all the information , please refer to link below we have most of these columns in the raw file and import in to our own datawarehouse.

https://marketing.adobe.com/resources/help/en_US/reference/datafeeds-reference.html

So I am basically using this information from the raw data and trying to identify the visitor Id, a while ago when this was implemented, the adobe visitor Id has been set up with evar7. So  for example , basically if I visit the website the first time (visit_num =1 )  the evar7/Adobe Visitor Id lets say is xyz123abc , If I do not delete cookies and come back  to the site 100th time (visit_num = 100)  then I get assigned the same evar7 /AdobeVisitior Id = xyz123abc , just an FYI for all 100 visits the visid_high and visid_low value will always be same irrespective of the number of  visit.  But the data discrepancies I notice in the raw data is multiple users with different visid_high and visid_low have the same AdobevisitorId. Since we get the geo city ,geo country, IP all these values are different for the same adobe visitorId.  I am not sure if there is problem with the setup.Different sessions with same AdobeVisitor Id.

Thank you so much for all you help ankits28281247

[Ankit_Sharma_]

To me validating implementation by try and replicating the scenario would be the best bet here. like if this is happening from the same type of browser / System etc.

[Locutus243]

We are having a similar issue. We have a raw data feed which includes our internal userID and the Adobe allocated visitorID. Therefore we should see a one to many relationship between custID and visitorID to account for cookies, multiple devices etc...

What we're getting is the same visitorID being allocated to upto 100+ custIDs (which are all unique to an individual).

Did anyone ever get back to you with a resolution?

[Shaista_L · Accepted solution]

Based on more research, I got the answer to my own question. I used Adobe analytics debugger and visited the site blocking cookies and that was the answer to my question. When a customer blocks cookies or deletes cookies and visits the site, all of these users /customers get assigned the same Adobe Visitor Id.

[PratheepArunRaj]

Dear Andrey Osadchuk,​ asheeshp​, @ursboller,

Do you have any inputs for the question from @Locutus243?

Thank You!

Arun

[Andrey_Osadchuk]

Locutus243, what is the percent of such Visitor IDs (each is linked to hundreds of Customer IDs) in total volume of the authenticated traffic? — If it is absolutely insignificant, maybe a part of the customers are from internet cafes or online kiosks...

I have heard one web analyst working at a bank had a challenge — a significant share of traffic to Personal Cabinet was from offline branches where Customers could use shared devices (laptops). Another example is the computers at the airports. Just imagine how many people may use the same device (same cookie ID).

[Locutus243]

It is around 3% of our total traffic. Which still felt high for shared areas...but our industry may mean there is a higher than expected use of private browsing or clearing of cookies so I can chalk it down to that.