Cool article!
I spend a lot of time completing quests that are a lot of fun, but not profitable. They will be at some point in the future, when I have learned better skills, but they're not yet. The profitable quests available to me at my current level of skill are not that fun. The more time I invest into them, the less time I can invest into training my skills for the fun quests, and the longer it'll last until the really fun quests become profitable.
So what to do? Put all my energy into a profitable but not that fun quest, or focus on the fun quests that are not profitable yet?