Isn't it obvious? It's not a thank-you letter.

It's preying on creators who feel their contributions are not recognized enough.

Out of all letters, at least some of the contributors will feel good about it, and share it on social media, hopefully saying something good about it because it reaffirms them.

It's a marketing stunt, meaningless.

gaigalas, my toaster is deeply grateful for your contributions to HN. It can't write or post on the Internet, and its ability to feel grateful is as much as Claude's, but it really is deeply grateful!

I hope that makes you feel good.

Exactly. If you're so grateful, mail in a cheque.

By that metric of getting shared on social media, it was extraordinarily successful