G&H, A&S, Huntsman and possibly a few others make most of their money with their RTW offerings.The problem the Row has, is that the cost of the rent means that they should really be a luxury department store style business and not a niche men's tailors or outfitters.
Huntsman spends millions a year on their bespoke side, I doubt they get that back in with tailoring alone. From what I've heard lately they are now trying to become a lifestyle/ fashion brand.
More like buying a well known brand name as well. Most copyright laws don't apply in China and some "clever" locals have registered British tailoring houses' names as their trademark, which barrs the original ones from dealing under their name in China.Some have been bought by rich benefactors who want the cache of owning a slice of British history
Crompton generates quite some traffic for his customers and especially those who sell RTW items or accessories do benefit from it. The bespoke side probably not so much when the price tag tends to be enormous. At least that happened when he promoted Sexton.