Does anyone know what is taken into account in calculating the richest user title? Is it sP alone, are items calculated as well, maybe number of pet slots?

Curious about that, too. I was gone for about a year and I think I was somewhere around the 98th spot when I left and now I am quite a bit under 50th mark. Had a lot of sP in my shop till, but not much else changed in my account during that hiatus, so I guess it's just sP?

Just sP. The counts been broken since the server move.

Unless you have >4 billion pure sP your likely truly not even top 100.

Richest user is >52bil pure sP

... It's a joke right now. Since the last downtime, it's broken beyond belief and counts your onhand sP over what you actually have saved. Which, right now, to be the richest user would have to be over 4bil sP.

When working normally the rank goes by the SP you have including in your vault (and I think shop till? I can never remember that part). However as noted above, it has not been working right since the server move - first it was comparing only your on-hand SP against everyone else's on-hand SP so you could easily go up or down 1000+ places with some questing/spending, and now it's either gotten stuck on one rank (mine seems to, at least), or it's comparing total SP against everyone else's on-hand only SP. My rank hasn't moved in several weeks and it's definitely not showing the right place.

There used to be a page which would show total account worth, including totting up the value of all items owned, but they removed that page some time ago as it was causing a significant drain on the servers.

Thanks everyone, it's a lot clearer now.