Is a daily quest system worth the trouble?
I realize the purpose of daily quests in PBBGs is to get me logging in, and they can be useful to get early resources (though I prefer one-shot tutorial quests!).
Over time, though, dailies can become chores, and that tends to push me away from a game. Also, quests can dictate how you play, and the delta between how I want to play, and how the quests want me to play, may be where I really start to dislike dailies.
Bottom line: if a game has to use dailies to manipulate me to log in, that tells me it's not worth playing.