Count visitor uniquely across the browsers and devices

[VidhyaAk1]

We have internal site where user can login using the customer ID.
Currently we are capturing the ECID and MCID in the analytics.
But when we are checking the unique visitor count for month the count which we are getting is more the actual total customer count.
(I know that UV metric count the visitors separately if user uses different browsers and devices. due to this the UV which we are getting is more than actual count.)

If we want to identify the visitor uniquely across the browsers and devices together then what would be the suggested approach ?

[Meghan_Powers]

You could definitely do this offline using the customer ID (can export data via Data Warehouse and do it there).
If you wanted to do it in Adobe Analytics UI, you can import data using Data Sources, API, or import classification table and join the data there and then upload them.

[Jennifer_Dungan · Accepted solution]

We have a Customer ID (it doesn't represent all of our users, since there can be a lot of access without an account on our sites), but for known users, I use a calculated metric.

First I create a segment for:

Custom ID Exists

HIT

     Customer ID exists

Then I use this segment in my calculated metric with the "Approximate Count Distinct" function:

Unique Known Customers (Approximate)

Custom ID Exists [

    APPROXIMATE COUNT DISTINCT (dimension) [

        Customer ID

    ]

]

This makes sure I only count users (based on hits where they have an ID), in my metric. Technically you can do this without the "Customer ID Exists" segment, but the unspecified will be counted as 1 more unique user, hence why I exclude it... this way, when I break down my metric by Customer IDs, I don't have one random unspecified row.

[VidhyaAk1]

Hi @Jennifer_Dungan 

I have used this  APPROXIMATE COUNT DISTINCT function in calculated metric to get count of unique visitor. 
but client asking me that is there any absolute function get this count ? they don't want to use approximate one.

[Jennifer_Dungan]

Not that I have seen sadly....