Send EMPTY ENVELOPES to friends! (Wait, what?! - and, WHY?!) #WTF

"Why did I receive an empty envelope?!?" they will ask.
"Who sent me this empty envelope?!?" they will wonder.

"Prank It Forward!" 
Send Empty Envelopes to friends or family today!

IMPORTANT: Please pay attention to the difference between SHIPPING address and BILLING address!

(We hope this isn't necessary, but, just fyi:
"Shipping Address" is where we will SEND the Empty Envelope!
"Billing Address" is you - the address matching your form of payment.)