Another datapoint from the late September-early October rush of titles with early ranks made the charts. This time, it’s One Piece Film Z, a release split between DVD and BD/DVD combo pack sales that totaled a little over 6000 between them in their opening sales week. You can check the full list here while it’s up (screenshot after the jump).
A slight wrinkle here compared to previous cases is that this combines multiple release formats for the movie. My rough-guess formula pegged the BD/DVD combo pack itself as 4591 units, slightly above the 4451 threshold on BD for that week, but not unreasonably so (it would have been below it with a 10% overestimate). The series also had a DVD release which I tracked on amazon, and using the S=(6944*(R^-0.4))-60 formula on those two weeks of data (one of pre-orders, one of release-week orders), yields an expected total of about 2018 DVD-only copies. So the total estimate would be a 6609 copy total, which is pretty close to the actual value (off by ~7%).
I really need to do a better job of anticipating that there will be splits when I make these predictions. The new formula dictates a shallower slope, meaning less immediate drop-off with rank, meaning “inferior” versions can still add significant amounts to the total figure. Looking back at it, I’m also worried I may have mislabeled the “uncut” version of DBZ: Battle of Gods as DVD-only when it was a less-fancy version of the limited edition, but still a combo pack that will count as a BD for tracking purposes.* I’ll see in a week (those predicted totals are pretty high), but it would have been nicer if that release could be more clearly labeled.
*If somebody has bought the uncut version and it’s not DVD-only, please let me know. The amazon info and reviews offer contradicting stories.