[Onkel Neal]

Amazon will now start weighing a product's overall rating based on the quality of its reviews—and a few other factors.

http://www.pcmag.com/article2/0,2817,2486445,00.asp

Amazon's new weighted review system will use machine learning to ensure that the best reviews—as defined by Amazon—are prominently featured on a product's page. Presumably, this will also help Amazon reduce the number of crappy and/or bogus reviews that can sometimes be found on a product listing.

Makes sense.