Mechanical watches as a rule need to be wound, but watchmakers like Rolex discovered ways to make their watches "self-winding" -- actually capturing the motions of their wearer moving their arm and wrist, and using that energy to keep the watch wound and powered. Where the quartz powered watches had second hands that "ticked" once per second, the Swiss watchmakers invented an automatic movement that had the second-hands of their watches moving eight times per second, creating a more fluid motion. In short, the Swiss watchmakers had their products deeply entrenched in the minds of the public as statements of wealth and style. This, combined with a newfound ability to produce functioning watches cheaply, left the door wide open for the manufacture of replica watches.
Previously, manufacturing timepieces was prohibitively expensive for the common consumer but the advent of the quartz watch led someone to the idea of making one, but putting the name "Rolex" on it. These early replica watches were not terribly difficult to spot, but the fledgling industry grew up and today's replicas are spot-on spitting images of their namesakes, from the size, shape and color, to the movement of the second-hands, to the weight of the watch itself. In fact, many people believe it is possible to tell a fake watch by the second-hand "ticking" but that's no longer the case with the high quality replicas manufactured today.
