Visitor ID, Declared ID, MID, MCID, which one is used for what?

[#1]

So I'm interested in the cross-solution capabilities to track our visitors across our solutions. (Analytics, Audience manager, Campaign, Target). Though i'm finding a couple of different ID's and I'm not sure what the specific differences are and when to use them.

Campaign documentation mainly talks about visitor ID en declared ID, and from the looks of it, the declared ID is preferred. But reading the documentation on the Marketing Cloud ID service it mainly talks about MID or MCID. Could you please point me in the right direction?

[#2 · Accepted solution]

Great question!

MCID is a web technology that is used to ID a logical device (browser cookie) across multiple Adobe solutions. For example a single visitor should have the same MCID value across Target, Analytics, AAM, and other web based Adobe solutions. This allows things like A4T, Audiences, and other Core Services to work correctly.

A declared ID/Customer IDs are a ID that you set based on knowing the visitor. For example, you might set a declared id of a hashed CRM ID after the customer logs into your website. This is an ID that you might know about that visitor to connect offline data.

Adobe Campaign obviously doesn't use cookies since it's primarily works through emails. Using a declared ID here is more practical than trying to retrieve a cookie value from a webpage.

I've also tagged our Campaign community manager here incase he has any additional context

florentlb - Anything to add here?

[#3]

Hi,

In Campaign, the visitor ID is stored in the "source" field of the recipients tracking logs.

Florent

[#4]

Hi!

Indeed nice question. Campaign works with MCID (which is the latest name for visitor ID from a Campaign point of view) or declared IDs.

By default in Campaign, recipients/profiles that generates tracking (for example who have clicked in an email) have an MCID assigned. This way profiles that have such an ID are recognized in the different Adobe solutions you use in case you exchange data. And if you want to reconcile data based on specific fields/values you still have the possibility to use a declared ID.

Hope this clarifies a bit (I was just speaking from a Campaign perspective).

Florent

[#5]

You aren't able to see which MCID is assigned to each specific profile within Analytics. I'm not sure about Campaign. florentlb​ Do you know if this can be done on the Campaign side?

We use the MCID value as the ID for reporting purposes (assuming they don't have a legacy ID). This means that the number of visitors in any given report is essentially a count of MCID values within Analytics. While this doesn't allow you to view the actions of a particular MICD value, it does allow you to view trends.

[#6]

Ok, thank you for the explanation from a campaign perspective. I do have a follow up question on this. How can I see which MCID is assigned to the which profile and how can in reconcile this with for instance Analytics data?