Same-session metric tracking

[chrisw78940856]

We've come across a use case where it's important for us to track when a visitor completes a transaction within their first session upon entry in to an activity.

My question is: What's the best way to do this?

I thought about incrementing a cookie value by 1 for each new session, and only tracking event if cookie value is 1, but I'm not sure if there's a more efficient way to do this.

Otherwise, can I pull the SessionID from the existing mbox cookie and use that value?

Appreciate any support here.