Comments by Gavin Coates (Top 2 by date)

I know the user is a returning user anyway as I save the username, but this approach does make a lot of sense. If the Web App is considering the user to be a new user, then it makes sense to do so from the analytics too. Also it means it can be easily configured from the front end.

How often are session IDs recycled? What would be the likelihood of the same user being given the same session ID again within 24 hours, or 30 days?

I'll have a play around with this and see what works best.