“We’ve gone from 12 million customers in 2019 to 34 million solely based on word of mouth,” said David Velez, the company’s co-founder and CEO. By September last year, the company was onboarding 41,000 new customers per day. NuBank prides itself on having a $0 customer acquisition cost. Velez said the startup spends what would be marketing money on “great salaries” and superior customer service, which in turn creates “fanatic” customers who share their love for the brand with others.

https://techcrunch.com/2021/01/28/fintech-darling-nubank-raises-blockbuster-400m-series-g-at-25b-valuation/