Hearthpwn

I think your right kunigundee. I have a theory that when you cycle a quest it pulls from your backlog, if you have one. I have yet to test it. 

I'm not sure if its intended or not either, and there may actually be a limit, so far none of my friends who play sporadically have been able to complete their entire "backlog" as I've theorized. I'm not willing to hold back my quests for months at a time and count them all just to find out. But from the week I wasn't playing I did get the exact amount I would have if I had been. 

Perhaps if there were someone who knew about code, could look at the coding of the game?  Not sure if that's even possible with copyright laws and such. Or we could just get an official response. *Hint-hint* *Nudge-Nudge* 

I enjoy it though because I do have a life and sometimes I need to forget about the game and not feel like I'm missing out on quests that are disappearing. Its a good balance in my opinion. 

So after testing my theory I've come to a conclusion as to how daily quests work. You truly do only get one per day. However if you already have three quests on a new day, then your new daily quest goes on a backlog of sorts. Now if you complete all three of your quests. The next day your slots will fill up with your backlog, plus your new quest. So therefore if your not a person who completes all their quests every day, then you'll have a tremendous backlog and will receive three quests everyday until you complete them all. I tested this through not completing my quests for a week. Then I completed them all yesterday and this morning I received three quests. Before I was only receiving one.

I had been confused about this for awhile, because I have friends that I work with who play the game and say that every day they complete three quests and get three new ones the next day. It was frustrating, but after asking them I found out they would regularly go on bouts of not playing for weeks or even months.  

Hope this helps.