I accepted Amazon's offer for a one-month free trial of Prime, and I recently had an experience that will probably make me pay to continue the service.  I ordered a small electrical connector on a Thursday at around 6pm, and hoped to get it (with free 2-day shipping) by Saturday at the latest so I could bring it on vacation with me.  It turns out it arrived on my doorstep sometime on Friday afternoon, probably around 3pm.  I checked the label on the package and it said it shipped from Kentucky.  That means an order was placed electronically, processed, picked from a warehouse, packaged, shipped from Kentucky to New Jersey, all in less than 24 hours.  Oh, and it shipped for free (assuming I paid for a membership).