Reputation is definitely a critically important function. If you had a good reputation system, suddenly all the spam and scam in the world can easily be ignored.
And, basically, a 'reputation' system, in its most general sense, is simply a concise and quantitative description of the experience everyone has had with a person, product or service. And that is exactly what Canonizer.com is all about.
You point someone to your reputation survey topic, before you start the deal. You can point out that if they are disappointed with your service, they can join a camp describing such.
Then, if they have a bad, or good experience, they can create a camp (or most likely, just join a camp someone else has already started, describing your particular experience) and so on. No camp can be filtered by anyone, giving a true open and honest measure of experience that everyone can trust.
Imagine having one of these on your e-mail in-box. You could set your personal canonized reputation score, below which no mail gets into your inbox. If a particular one does make it through, and you don't like it, you give it a negative reputation, and nobody else will have the same problem. And if something does make it through, you can trust that it will be worth your time.