Good luck to them for ranking....but it is unlikely to have long terms legs because Google is constantly trying to deindex sites like this it and revenue from affiliate links isn't going to make the site owners competitive in any way once the free traffic dries up.
My understanding is that Google recently commented on hyphen sites and in essence indicated they had no issues with them as long as the rest of the aspects (content, links etc etc) were ok. Their exception was double dashes, e.g. car--insurance, which they will specifically target as being "non quality search returns".
IMO Google cannot clamp down or penalize in any way a domain with hyphens, i.e. single hyphens between words, because that is exactly how the robots see the domain in any case. CarInsuranceQuotes.com is seen by the robots as Car-Insurance-Quotes, so is CarInsurance-Quotes or Car-InsuranceQuotes ... right? Google would have to change the whole HTML/URL system used globally and that wouldn't work.
Do an Adwords Keyword search and include hyphens and you get the same results as typing in spaces (Car Insurance Quotes vs Car-Insurance-Quotes)
As a domain for a business based on the subject matter of the domain I agree that hyphens don't really work however for making money from advertising or AM they are terrific, as per some examples in this thread.
cheers,
Mike