Same experience with my users: day 1: why do I need another app/website/etc day 2: ok fine, but what's with the threading? day 3: whoa, this is pretty nice.

Same experience with my users: day 1: why do I need another app/website/etc day 2: ok fine, but what's with the threading? day 3: whoa, this is pretty nice. day 4: <feature request> day 5: <feature request is live> day 6: mind blown