Unlike a lot of Tanaka's other stupid decisions, I think the Guild Mark system has a place in this game. It was Tanaka's dumb idea to have abilities and traits tied into it - I found that part really really foolish - you reach the level for the skill but you're locked out of the skill until you get the right # of points to buy it? Unnecessary time sink.

However, I do think that the Guild Mark system can be revamped for the better.

I'd definitely go with something like a combination between Mihira's and Catapult's ideas and also the idea about class-specific gear (nothing too powerful, but stuff you can use along the way to level 50) or even vanity items specific to the class (stuff to wear while you're idling in town) as a means of getting you to use Guild Marks. The issue here is, there are players like me that only have a few guild marks laying around, then there's other players that grinded the crap out of guild marks, and I'm pretty sure there's no easy way to satisfy those players.

Maybe consumables that benefit/buff certain skills you use as a particular DoW class, and being able to buy potions or hi-potions for practically "free" would be a good way to allow us to burn off our marks. And yeah, retrofitting the GC system into the GM system would make it a lot more fun too, give yourself titles as you rank up in the guild - make the guild more interactive with your class.