Apple's Reuse/Recycle Program

I was interested in sending in my 32gb 4S to Apple's reuse program and using that money for the iPhone 5 and then all I'd have to pay is the ETF for Verizon. Does anyone with experience with this know how long it takes to get the gift certificate from sending in your old phone? Also, since it's a gift certificate does that pretty much rule out the option of being able to use that money towards pre-ordering the iPhone 5 or would it be possible to pre-order in the Apple store using the gift certificate?