cfx211 - 9:57 pm on Dec 12, 2003 (gmt 0)

I estimate a 30-40% overlap in home and work usage for our site, but this is a very site dependent trend. Our busiest account segment averages about 2.5 cookies per account over a 6 month period.

We do this by keeping an account_id column on our cookie table and then updating it when someone logs in. Based on that I then create an account to cookie xref table.

I was actually talking about what happens when you try to use two separate systems to keep track of unique users. I would worry about making sure that you were not double issuing unique identifiers using each method once.

Maybe one day the cookie would not issue for whatever reason so you used the fallback method. The next day they come again and this time get the cookie.