The answer is… Guns N’ Roses.
In his book “It’s So Easy (And Other Lies)”, bassist Duff McKagan revealed that email marketing was a key component of building the band’s fan base:
“As soon as Guns began to play regularly in LA, we started up a phone and mailing list. We obsessively made sure people who came to shows signed up – well, actually, what we did was send stripper friends out into the audience and have them convince people to sign up.”
There are 2 important takeaways from this story.
Perhaps you won’t use strippers to compel subscriptions, but if you’re a veterinarian cute kitties might work.