If your $500m budget is only returning $1b you are probably losing money and are wasting a ton of your budget. For what it's worth, Duolingo raised $83.3M , so

If your $500m budget is only returning $1b you are probably losing money and are wasting a ton of your budget. For what it's worth, Duolingo raised $83.3M , so it's not like they bootstrapped to that growth. The growth hacking you are referring to has a large cost too. You need disciplined and very creative engineers, copywriters, analysts, a culture of testing, social psychologists, marketing experts, directors, etc... I bet Duolingo's marketing costs are well into the millions a year in Human Capital. The stories of guys going from 0 to whatever cheaply are not the same stories as a company with 83 million in funding.