If you google "offline progression", you'll find three games mentioned: Earthrise, Eve, and Alganon and - revealingly enough - my blog posts here. That's it.
If it was not so sadly revealing about the current state of the MMOG industry, it would be funny. Here is a gaming genre primarily based on monthly subscription, where you pay for 24./7 access, and yet out of dozens of pay-to-play games, only two current games offer any form of offline progression whatsoever?
It seems to me to be so fundamentally obvious that if you can provide a 24/7 benefit for a customer's monthly subscription fee, you should give them something, if nothing other than some kind of ongoing "thank you for staying subscribed even if you can't play much." A functioning, meaningful reason to keep subscribing even if one's ability to stay online diminishes over time, or even if one wishes to try out another game.
Is that not obvious to everyone? I mean, is it just me or what? How can one explain that the entire genre basically ignores what would be an easily-coded and included major draw and selling point for casual and time-starved players? Heck, you could get players to subscribe to several games concurrently if those games had significant off-line progression.
It's really mind-boggling that this obvious feature has been so ignored by the industry.