When I originally abandoned the game about a month after launch, my rogue was in her thirties. When I picked the game up again and rerolled as a cleric this summer, I also started logging onto my rogue again, though only to invoke (pray to the gods) and receive the associated benefits of currency and experience points.
Now my rogue has hit sixty, with most of the last couple of levels gained purely by invoking. I'm not entirely sure how I feel about the fact that you can fully level a character to max simply by logging in every day, without actually playing "properly". On the one hand it's a nice way of getting an alt to the level cap without having to put a lot of effort into levelling, plus it's one way of skipping questing content that you've already repeated one to many times.
On the other hand it feels weird that you can't really "pause" playing a character, to later pick it up again where you left off, unless you're willing to forfeit the (considerable) benefits of invoking every day. It can also be somewhat challenging to get back into actually playing the character if you've gained twenty more levels (plus associated new powers) since you last went out into the world and your gear is now hopelessly outdated for the content that you should be doing.