I think I have surprised myself at the amount of gitd stuff that I have - unopened - lying around. Nick did mention in passing that he doesn't think there are that many gitd toys, and I told him there's more out there than he can ever imagine.
The advantage of not doing one a day is that if I have a whole collection of stuff that I want to open at one go, I can just save up the requisite number of days and open them all up at once. I have a whole weeks worth of Supernaturals that were just sitting there taking up space, and I really wanted to clear out the space, so I decided that they should be opened next.