Answer: When it starts acting like an old one.
In late January 2009, I rolled up a new character on the Borean Tundra server, a brand new server that had opened on January 16. The server was just over a week old, and since it was closed to all new transfers for three months, I thought it would be a lot of fun to start over in brand new territory — a born-again newbie on a born-again newbie server. I was most looking forward to running instances at level, with other people my own level, instead of being innundated with “Paying 5G for wc run plzplz!!” in Trade and General. So, with an eye to being desirable for pugs, since I didn’t want to join a guild, I rolled up a blood elf priest.
This was not my first priest. I already had a priest on my home server, but I had not played her past level 34 and so long ago that I had forgotten how to play her, and I’d deleted her awhile ago.
My original intentions were to stay on Borean Tundra, at least until the AQ gates opened (I had missed much of that hoopla since I had been in the process of changing main servers at the time), or at least until it stopped being fun. I didn’t realize that “stopped being fun” would come first.
At first, BT was all I had intended it to be. The newbie zones were full. There were groups everywhere looking for healers, and I had more opportunities to pug any instance I wanted than I could do. I did at-level pugs for RFC, WC, SFK, RFK, and SM graveyard and library wings. I had offers to do Gnomer and DM but I didn’t end up going to those due to poor timing. I was counting every copper and silver; I didn’t earn my 35g for mount money until I was almost level 35, and that meant forgoing my own training for 32 and 34.
But shortly after I got my mount, I realized that the times were a-changing.
There were enough 80s on the server now that I could see massive changes in the economy. Suddenly, there were twinks appearing and prices on gathered goods were going rapidly upward. Within two days of getting my mount, I had 40g again. There were fewer and fewer “lfg RFC” and more and more “paying for RFC run!!!” in city chat. People weren’t as interested in running instances, even in their mid-30s, and more interested in just making the pell-mell push for 58, Outlands, 68, Northrend, 80.
In other words, it was becoming my home server, without my friends, my husband, access to my guild bank, and the earning power of my 80.
I went to BT for two challenges: playing the content thoroughly at level, and having to count my coins and make careful choices. These began disappearing rapidly at the mid-30s, and suddenly it wasn’t different anymore. So I transferred her “back” to Whisperwind, familiar names in chat, and an 80 hunter husband who’d rush her through whatever she wanted.
It was something of a letdown, but it was fun while it lasted.