How Facebook’s Reliance deal upends a $1 trillion digital arena

An innocuous WhatsApp “Hi” could end up transforming a $1 trillion industry.

Facebook Inc. bought its way into India’s internet commerce sphere last week with a $5.7 billion investment in RelianceNSE 2.79 % Industries Ltd., a sprawling conglomerate in everything from telecom to energy. They launched their first pilot within days, a program covering three Mumbai neighborhoods where consumers can send that monosyllabic greeting to a designated number, bringing up an in-chat interface through which they then browse a catalog of goods on Reliance’s Jiomart, place an order and arrange for pickup.

That in itself is novel to much of the rest of the world — shopping via a messaging platform. But in coming weeks, the pair are likely to add online payments — a simple move expected to create a potential leader in India’s frenetic digital payments arena.