Might want to think about having a small physical footprint to keep square foot costs low (maybe a booth instead of a storefront, for instance) for starters. Might also want to think of packaged programs (i.e. $19.99 for a set up of 3 social media apps on a device, a 10 minute tutorial, and a 2-page handout) so that you have something very specific and tangible to sell. Seems like a good idea if you can get in a small space with a lot of foot traffic. Have you thought about the all-important question of who you DON'T want to sell/market to?