I still don't quite get it given I have never worked high enough or in a big enough corp. What kind of mission a person earning $19k a day have to do at the destination to justify the cost? I imagine to earn this much their main responsibility is to lobby / influence someone important (at dinners, golfing and such). Otherwise, if there are no outsiders involved the whole thing could be just done online. If it's about lobbying though - does it have to be done immediately and 3-4 times a week?

Another example that comes to my mind is a highly skilled expert in repairing some important machinery, e.g. ship engines or factory lines.