Don't do this. I'd like to repeat: DON'T DO THIS! This is an extremely jerk move to do. You're basically saying to everyone who sees you 'my online time is more valuable than your online time.' This is not going to win you any friends, especially for someone who just had to wait a half hour to get in because you were to much of a jerk to log off when you were done playing. And this is the sort of thing people will remember later on in the game when looking for group members. People have long memories for when someone's been a jerk.

Oh, and those long queue lines? They get shorter whenever people log out. That's how it works. So every person you find who is AFK for a half hour, an hour or eight hours is just making the queue times that much longer. When you're done, log the heck out. Suck it up for queue times, it's better in both the short and long run for everyone involved, including you.

I'd like to see the AFK stores removed entirely from the game actually. Not only are people abusing them like this, they're also annoying, rarely worth buying from, annoying, get plopped down in the most inconvenient areas, annoying, tend to slow frame rates when you get a bunch of them in an area.. oh and did I mention they're ANNOYING? Seriously. We have an auction house. Use it.