Mark Zuckerberg has defended Facebook's advertising business model in face of criticism from Tim Cook.
The Apple CEO hit out at the revenue models of rivals like Google and Facebook earlier this year, stating that Apple does not sell personal user data to advertisers.
"When an online service is free, you're not the customer. You're the product. But at Apple, we believe a great customer experience shouldn't come at the expense of your privacy," Tim Cook said in September.
Despite previously delcaring his respect for Cook as a leader, the 30-year-old billionaire felt compelled to hit back at the Apple boss in a recent interview with Time.
"A frustration I have is that a lot of people increasingly seem to equate an advertising business model with somehow being out of alignment with your customers. I think it's the most ridiculous concept.
"What, you think because you're paying Apple that you're somehow in alignment with them?
"If you were in alignment with them, then they'd make their products a lot cheaper!"
Zuckberg was also asked about emerging rivals, such as Ello, which use the paid option instead of ads.
"Our mission is to connect every person in the world. You don't do that by having a service people pay for," he responded.