We get it. We know that a good UX is good for the company. I recently observed some user testing and at the end of the user journey two of the participants smiled and said something like "I've have mixed/bad experiences with [Company X] before but this makes me feel good about them." That sentiment is worth money for the company.
But, in a large company (think > 50,000 of employees) it can be a long way from UX design to delivery of an interface and the small things that contribute to great UX are often the first things to be sacrificed on the alter of deadlines and costs. But we know that smiling customers are valuable to the company.
I'd be really interested to hear how people have had business cases built to support the delivery of a quality experience in large companies. How do we put a value on a smile?
How can business cases be built to support the delivery of a good UX based on the emotional responses of customers, not just conversion rates?
Update/further explanation: If you design a UX and the developers say "If you want it like that it'll cost an extra £20,000 and take a week longer" (they're probably exaggerating) it needs a solid argument to rebuff it. How, in a corporate setting, do we put good UX design on a strong enough footing that it can stand up for itself in these sort of discussions? (We can't rely on everyone just understanding the value of good UX)