The same concept is part of the reason Warren Buffet loves insurance companies.
Policyholders pay premiums up front, which the insurance company knows it it will return at some point as claims. In the meantime they have access to a pool of low-cost cash called 'float'.
Using that float to invest however they please allows the insurance company to run its core business almost as an incidental loss-leader - the real deal is the investment returns.
But surely the WTS are not that money-motivated??? :-p