It's a very simple concept that shouldn't really come as a surprise to anyone. That said, I spend a load of money on adverts every day, am regularly sending ove

It's a very simple concept that shouldn't really come as a surprise to anyone. That said, I spend a load of money on adverts every day, am regularly sending over JS snippets which I'm well aware will be executed on the machines of millions of people, and yet the thought of using adverts for this sort of thing never occurred to me.