The current rhetoric when it comes to the failings of online reviews is to point at fraudulent reviews. I posit that, rather, it's the lack of weighting reviews by the expertise of the reviewers. Clearly the reviews of a hardware engineer at Google should have more weight to them than an average consumer (on products like this), because as bkmartin points out, the average consumer has no idea as to the true quality of a product. Perhaps the cable does work for them. Perhaps the cable mostly works, but the wire gauge is under spec and 1 out of 100 people end up with a fire. That won't be reflected in the overall rating of a product.

Case in point, the Juiced Systems product that Benson reviewed as 2 stars is currently listed as an overall 5/5 stars. In Amazon's defence Benson's review is currently displayed at the top of the reviews. So any shoppers that go through the effort of reading the reviews will quickly see it.

But this product shouldn't be rated 5/5 overall, and because it is, many consumers who can't be bothered to check the content of the reviews will be burned.

This, to me, is a greater problem than fraudulent reviews. Fraudulent reviews can be solved by getting more regular customers to review products they buy. Uber is a great example of UX design that gets customers to review the quality of their service nearly every time. But even if Amazon or other retailers achieve a higher rate of reviews by actual costumers, the non-expert bias will remain.

Of course the trick is, how do we determine which reviewers are experts? Most review systems have a helpfulness rating on each review which could be used to weight reviews in the overall average. But that's only a proxy for an expert rating, is easily cheated, and it's harder to get customers to rate reviews than it is to get them to at least review the product.