IMO, this is a problem with many things - it's very easy to focus on that which is quantifiable, and ignore the fuzzier stuff. For instance, I did a comparison of Linode and Slicehost which has proved quite popular, but one of the things I stated up front was that while it's possible to measure costs and things like memory and disk, it's not really possible to easily compare service, especially as for the most part, hosting is invisible, and service only becomes critical in an emergency.
Economics in general suffers from this problem too. It's easy to quantify things related to money, but much more difficult to deal with the benefits from more abstract things.
Service is a feature that's much harder to quantify, but there _are_ ways of demonstrating it. One of the best recent examples I've seen is http://www.engineyard.com/, which lists its sales & support phone numbers on the header of each page. In this day and age, where phone numbers are being increasingly hidden, a company that stands out like that really makes a good impact.
Economics in general suffers from this problem too. It's easy to quantify things related to money, but much more difficult to deal with the benefits from more abstract things.