The Delta 4 theory, introduced by entrepreneur Kunal Shah, helps explain why most startups fail while a few succeed. At its core, it says a product must improve a user’s experience by at least 4 points compared to existing alternatives. Only then do users adopt it permanently.

Take Swiggy as an example. Ordering food used to require phone calls, waiting, and cash payments. Swiggy simplified everything: a few clicks, online payment, and faster delivery. The improvement, convenience, speed, and reliability, was big enough that users never returned to the old method.

Delta 4 also includes the Unique Brag-worthy Proposition (UBP). People love sharing exciting new products, accelerating adoption across their networks. WhatsApp survived despite Signal offering better privacy because the Delta wasn’t large enough to change user habits entirely.

In short, Delta 4 isn’t about building any product, it’s about building one that changes behavior, sticks permanently, and spreads naturally. Startups that master this have a real shot at success.