When you're getting married, you send out an INCREDIBLE amount of mail. Brides are probably the only people that are even keeping the US Postal System in business anymore. When was the last thing you got anything in the mail besides a Save the Date or wedding invitation? Exactly.
So, since you'll be sending literally the most mail of your LIFE, pondering why stamps cost SO MUCH, and hand addressing envelopes until your hands bleed, and the like, you might as well have some fun with it.
And what's more fun than getting a Custom Portrait Stamp ($100, Stamp Yo Face!) made out of your FACE? Send a picture of you and your fiance to Stamp Yo Face! and they'll get cracking, making you a custom portrait that you can stamp alllllllll over your various wedding shit.