Google has now added Google base ratings on PPC adcopies to indicate further authority of a brand, from what i understand this is only via brand rather than product for the time being. It is said that reviews increase element of trust on a brand and product and increase engagement and ROI many times fold if a review is good, somehow we seem to trust a strangers word and experience over our own logic when making a purchase decision!

This will be huge for the e-commerce businesses community, it's also a very sneaky way to increase usability on Google base by bringing more significance!