Google has been giving terrible results for product searches for a long time now. I tried to research a new dishwasher a few years ago and Google was a mess. Google's main problem right now is that they think they can stay ahead of the black hat SEO with algorithms. Take it from somebody who used to work in the anti-spam and anti-virus world ... you can't! You need to use more than algorithms, in particular you need to use feedback from your users. Google has a huge database of data on it's users. Google knows I've been using google and gmail for years, that I'm a real person, I use Google search dozens of times a day and I'm pretty technical. If Google had a "this is spam" or "this is not useful" button the would have millions of pre-validated curators to help them filter results.