Tell Somebody. "People Need To Know" says a customer

A customer told me he uses his iBeam watch everyday. He has some vision problems and is up frequently at night. "You have to let more people know about your watch", he said. "They need it". I've never spent any money on marketing but I'm thinking about it. Mostly people find me when they see a customer using the watch and ask about it. My customers are my best salespeople but since they can only find this watch from me I need to let more people know where to find me. I'm working on it.