True, but at the very least, we're reducing the set of all possible fraudsters and system-gamers.
How many of the fraudulent reviews on Yelp do we really believe are coming from fraudsters with this level of sophistication? My guess is that it's a pretty small percentage. Seems far more likely that most bogus reviews are coming from competitive small business owners, paid-off users, and other relatively average folk with a minimal level of technical understanding -- or even sufficient malice to drive them to become more sophisticated. (It doesn't help that Yelp may, or may not, be assigning greater weight to negative reviews unless/until a small business owner buys into their advertising).
How many of the fraudulent reviews on Yelp do we really believe are coming from fraudsters with this level of sophistication? My guess is that it's a pretty small percentage. Seems far more likely that most bogus reviews are coming from competitive small business owners, paid-off users, and other relatively average folk with a minimal level of technical understanding -- or even sufficient malice to drive them to become more sophisticated. (It doesn't help that Yelp may, or may not, be assigning greater weight to negative reviews unless/until a small business owner buys into their advertising).