I think it's a great idea!
1) 7 days from now
2) I'm sure many people will think he still has the album set on his birthday, so I think he'll have impressive second week sales.
3) First week sales are always impressive for everyone. Drake is one of the few rappers that open with huge numbers the first week. Since it's his B-Day the following week, he will maintain his sales for week 2.
Cheap, but smart move from him.