This is the ticket. Slack is operating on three principles. One, that their product actually has value commensurate with its price. That's a remarkable tenet

This is the ticket. Slack is operating on three principles. One, that their product actually has value commensurate with its price. That's a remarkable tenet for any product, and it keeps them honest. Two, demanding a high value for a product influences customers' perception of that product. By not discounting or downplaying the value at all, Slack builds on the psychological worm that you're getting what you pay for. This has been proven in (consumer) studies to make people like purchases more compared to items of the same price or free. Finally, they assert that the market exists and their customers have the ability and desire to pay for a better product (ddebernardy's point). All correct.