The opportunity might have easily been overlooked. The no-charge for bag check or ticket change could have been merchandised as just that: individual product features. It would have still delivered value to consumers. But by uniting it with values the brand holds - transparency, predictability, doing right by the customer - they enjoy greater value. The no-charge feature now embodies principles the customer believes in (or at the very least feels good about) and triggers a human connection shared with the company they are about to entrust their life to (it is air travel after all).
This is smart marketing. Giving what could otherwise have been only a rational benefit some emotional appeal makes it not only more compelling, it elevates the value consumers get by aligning with their personal values - at no cost to the company.