Birthday spam
The means of spamming someone on their birthday by presenting them with the words 'birthday spam'. This can be by any line of written communication including social networks, on paper airplanes, notes, etc... You should feel happy that people have taken time and imagination to come up with new ways to birthday spam you.
I had 60 pieces of confetti like paper all with the written words 'birthday spam' inside my birthday card.
Birthday Spamming
The act of getting many people to write happy birthday on one person's facebook wall, even though its not their birthday.
Person 1: Dude, why is everyone writing happy birthday on my wall it's not even my birthday.
Person 2: Because we were birthday spamming you.
Person 2: Because we were birthday spamming you.