I don't think it's the functionality/idea of the thread that draws people into the daily-thread.
I think it's just friendly, casual, community building, non-bitcoin content. I think making subs dedicated to other content should be priority #1.
Economics 101 dictates that if complimentary products exist, that increases demand for the compliment. Building subs, should drive up demand for both Bitcoin and the Bitcoin content. Bring more people in. And keep people who are here, coming back.