Useful but not sufficient on its own. Gresham&#x27;s Law, in various incarnations, including Akerlof&#x27;s &quot;The Market for Lemons&quot; suggests limitations.<p>A trusted third-party reviewer (Consumer&#x27;s Union, CarFAX, Kelly Blue Book) helps.<p>Anecdote: the last really big-ticket item I bought (automobile), I&#x27;d had positive experiences with two manufacturer&#x27;s products previously, but really didn&#x27;t care for their current offerings within the product class &#x2F; price range I was seeking.  The vehicle I <i>did</i> buy was one I considered based on its Edmunds review -- best in class, multiple years running.  Some years on, I&#x27;ve been happy with the purchase (though of course, post hoc rationalisation is a common fallacy).<p>For other products, other signifiers matter.<p>On G+ I detailed frustrations looking for a decent LED cabinet-lighting system.  I&#x27;d exhausted local, online (Amazon and major hardware&#x2F;lighting store) sources.  A recommendation from my G+ contacts was for Ikea.  The specific product didn&#x27;t work, but Ikea had another set of lighting components (separate cord, transformer, remote switch, and lighting elements) which has worked excellently.  Took a few weeks longer than intended to find what I was looking for.<p>Otherwise, I rely strongly on what local retailers will carry and stand behind.  Ikea, for some products, turns out to be a good source.  Factors depend heavily on what it is I&#x27;m purchasing and just how it will have to function.