First real utility appears
From a token to a utility
When Binance went live in July 2017, it introduced BNB for use on the exchange. Users could pay trading fees with BNB and receive a discount; the fee-discount model became BNB's initial core utility.
How it happened
Binance's official retrospective indicates that BNB was introduced alongside the exchange launch in July 2017 to be used for paying exchange fees and to offer a discount on trading fees. Sources confirm only the month, so no specific unverified date is asserted.
What it changed
BNB transitioned from a newly issued token to a practical tool within the trading platform. The fee-discount utility tied the token to real platform demand and laid the groundwork for its later expansion into a wider ecosystem and on-chain uses.