If there is money to be made, new firms will enter the market, increase supply, drive prices down, and thereby eliminate the profits that attracted them in the first place. If too many firms enter the market, they’ll suffer losses, some will fold, and prices will rise back to sustainable levels. Under perfect competition, in the long run, no company makes an economic profit.
— Zero to One: Notes on Startups, or How to Build the Future by Peter Thiel, Blake Masters