Good point in general - although it's important to remember that this phenomenon works both ways. Online forums, as a key component of social media, are recognized as being potent tools to help shape public opinion and perception. This can work for a product, or against it. Having created and run an online gaming community several years ago, with about half a million members and 25,000 visitors a day, I recall all too well how "sock puppets" in our own chat rooms as well as those of other gaming sites attempted to trash us for non-existent issues, effectively attempting to steer users away from us and reduce our market share; quite an eye-opening experience!
As others have pointed out here, online "experience" posts can certainly be helpful, but both negative and positive posts on a topic should be viewed as you might evaluate any kind of anonymous information: as anecdotal data points that may, or may not, be accurate, and that may - or may not - help you make an informed decision. If nothing else, whether you find the pros or cons more credible, these discussions will help you identify topics of interest to you that are probably worth further independent research. Keep an open mind -- but read with a critical eye.
