By contrast, AngelList founder Naval Ravikant is a little cheaper. He charges only $20 a pop.

Usage of Earn is not widespread, but it’s not unheard of in the tech world. Emailing lists of people in a specific industry (who said yes to this type of contact) is another option. When the company rebranded from 21.co to Earn.com, the announcement said, “The idea behind Earn.com is that we’ve built a positive-sum social network, where every notification is an opportunity to earn money.”

h/t: Inc.com