The Authy App, developed by Twilio, added WhatsApp verification as an alternative to SMS-based verification. The experiment showed strong user adoption, improved conversion rates, and decreased fraud when using WhatsApp for verification. Users preferred WhatsApp over traditional SMS due to its free nature, accessibility via Wi-Fi, and end-to-end encryption. WhatsApp's robust fraud prevention tools and unique phone number identification also contributed to the security benefits. However, not every user has a WhatsApp account, and pricing varies by country. Despite these limitations, adding WhatsApp as a verification channel can save money and improve user experience, especially in markets with strong WhatsApp usage.