I must declare an interest: I run a site, Feefo, an independent feedback forum.  However, what I say probably applies to most feedback systems, more or less significantly.

A difficulty that most businesses encounter in attempting to improve their search rankings is that there is little 'news' about their site that search engines consider relevant.   Recently, for entirely different reasons, we started an independent feedback site that temporarily had a remarkable effect on Google natural rankings.

Let me first explain the idea behind the site.  Put simply, it is to provide 'eBay style' feedback for any web trader.   If you trade on the web, you can send Feefo details of all your sales (usually automatically), and we ask your customers for public feedback on an independent site.  You put a link on your site to "see what our customers say about us." The basic service is free.

The main reason for traders to do this is clearly to establish their reputation (as on eBay), but there is also a big advantage: they learn plenty about their businesses in conversation with their customers, and another side effect is (in the case of a printer who joined) that it does wonders for staff morale.

We have only one 'major' customer at present: a shirt company called Charles Tyrwhitt, that turns over about £100m.  Because we sent out polite emails, and because our aim is to help customers as much as to help suppliers, we get a remarkable number of responses - up to 20% of shirt buyers, and a larger percentage for small businesses.  This means a large flow of 'news' onto our site.

Suddenly, about a month ago, Google raised our rankings in a number of key areas for Charles Tyrwhitt.  For instance, on the keyword 'formal shirts' we ranked 5th.  For 'mens formal shirts' we ranked 3rd, and, most astonishingly, for 'ties' we ranked 4th, even though ties are not the main business of Charles Tyrwhitt.  We then briefly got excited and made a mess of our linking, so we have lost our rankings for now.  However, the sudden appearance at the top of the Google rankings gave food for thought.

Because of our shortage of customers, there must be an effect whereby Google, or other search engines, view us as being in league with our single customer.  However, despite this, the flow of feedback (up to 200 feedbacks per day on ties) was sufficient for Google to believe that this was breaking news about ties.  And this is probably a correct assumption, since there is little other news about ties that is interesting. 

The lesson I learned from this is that a clear way to substantially improve your search rankings is to encourage as much feedback as you can.  I also suspect that our model - an independent website - is better both in offering more feedback, and in having more credibility with the search engines, but this is yet to be proved.  Our success so far has been remarkable, but it has been fleeting.