That may be good advice for a single individual. However, using a returns policy for trying out products costs money — and these costs get passed on to other customers.
Have you seen the returns line at Costco? Every day hundreds of products are returned, yet the store is doing great business selling items cheaply. It's customer service at its best, and that gets them customer loyalty. I had a plasma HD TV fail, one day after the warranty expired. One day! I told the returns desk, the guy told me to bring it in, I did and got a full refund of $1800. I then bought a different TV with more features (two years had gone by) for $1200. That cemented my loyalty to the store.
Its also wrong