A great trick

A friend of mines son has a great trick he plays on his friends. When they show him the great new watch they just bought he asks to see it and pops open the magnifying lens on his iBeam, turns on the light and examines the watch closely before pronouncing "it's a fake". After they freak out and ask him how he knows he says "it's all in the details".  He eventually says he "was just joking" and that it is real but they need to be careful. Their usual comment is "where did you get that watch?". He tells them iBeamwatches.com and you need one.