Online product reviews are a huge part of our lives these days, and often, they're the nearest thing we get to a 'hands on experience' before we buy something. But how do we know they're honest? Dishonest reviews are a serious problem for retailers (and indeed for content websites like dpreview.com) and a team at the Massachusetts Institute of Technology has been investigating why people are driven to leave reviews of products that they haven't actually used. Their findings might just surprise you. Click through to read more.