There's nothing quite like getting one over your parents - in a loving way, of course - and that's exactly what two brothers in the US have done.
Mike and Chris Ferry wanted to wish their dad - also called Chris - a happy 62nd birthday, but as the two of them live in Florida, and their dad lives in New Jersey, they had to think outside of the box.
Now on the surface of it, spending $2,000 (£1,513) on a birthday present is extremely generous, however, Daddy Ferry could probably think of things he'd prefer the money to have been spent on, rather than a giant billboard with his face and mobile number on it.
Alongside his mug and mobile number, a message on the billboard reads: "Wish my dad happy birthday - love, your sons."
Mr Ferry estimates he has already received around 15,000 calls and messages from strangers across the globe... and when we say 'across the globe', we mean it.
Speaking to Inside Edition, the birthday boy said: "Every state in the Union, Luxemburg, Kenya, Philippines, Caritas Island - that little island in the middle of the Indian Ocean, they tried calling me."
But of the thousands of strangers to wish him a happy birthday, a guy called Nick was the first.
Mr Ferry told CBS3: "Thursday morning I got a text that said 'happy birthday', and I said, 'who's this?'
"'You don't know me.'
"'How do you know it's my birthday?'
"'I read it on a billboard.'"
That moment right there is priceless, or worth $2,000 at least.
Mr Ferry said he has even become somewhat of a local celebrity off the back of the prank.
He said: "A waitress recognised me, she said, 'Oh you're the billboard dad.' So that's my new angle, I'm the billboard dad."
It's quite appropriate really that Mr Ferry is now famous among waitresses, as the prank started out in restaurants when the boys were children and would tell waitresses that it was their dad's birthday, even though it wasn't.
But despite being inundated with voicemails and messages, and even having to record a new voicemail message thanking well-wishers, Mr Ferry said the prank had ultimately been more heart-warming than annoying.
Speaking to CBS2, he said: "I'm getting things like, 'My father's birthday was March 16. He passed away. I'm contacting you in memory of him.'
"It's a cool story, and I'm right in the middle of it, so I love it."
It's just as well really that Mr Ferry has taken the joke in good humour, as the billboard is due to stay up until 6 April - way beyond his birthday on Saturday.