Learning the Guitar is a desire/dream/goal of A LOT of people. People love instant gratification so being able to offer a quick jump start into their goal is a sure fire way to get their attention (and business!).
But many people fear music and think that it takes a genius to be a good musician. To be a master it might take a genius, but to play songs on the guitar, sound good and have a great time is only a lesson or two away!