If you purchase this or other products from IMSI/Design, MacUpdate lists the serial number as either:
MTAP-9999-9999-9999-9999 : 0000-0000-0A00-0F00-0000
etc., depending on where you copy it from. If you enter this whole series of numbers into the Serial Number field of the embedded registration application (Snaks), it will just crash (with a stack overflow error in the Console logs). The problem is that the first part of these numbers,
is the serial number. The second part
is the activation code.
HTH. I had to Google this and found some comments elsewhere on MacUpdate for another product from IMSI/Design; I didn't get much help from their support channel.