I've been meaning to ask about this, and now I'm finally getting around to it.
At the moment I type this, my IPS forums (I always am updated to latest version) show "Who's Online 2 Members, 0 Anonymous, 368 Guests", but GA says 83.
Both supposedly record the number of 'users' within the last 30 minutes, but the IPS data is always 3-5 times the GA value at any given time. If GA is aggregating the data somehow, it's not by IP address, obviously, but I suspect IPS is counting unique IP addresses.
I'm hoping someone can explain the discrepancy and provide some options to better align these numbers via IPS. I do have the GA integration service enabled with my tracking code snippet from GA, but I'm not clear whether or not this is informing the IPS count (or if not, what this is actually doing for me if it's not providing GA with the data for its drastically lower count).
I forgot to mention, that my GA includes users of BOTH my forum and my mediawiki instance on the same domain, so the GA numbers should be larger in theory than what IPS shows me.
Thanks in advance