There are endless ways to market a new product and none of them are fool-proof. Social media: Twitter, Facebook, Google are the top three. You can pound the pavement and spread leaflets, hand out magnets, pens, etc. Every time you are talking to someone, give your product a little "plug" and sooner or later you will begin to see the return. Hang in there, stick with it, and it will pay off. It's very exciting when your see your first blog write-up where someone else mentions you and what a great idea you have. When you feel the time is right and you're ready to seriously market your product, hire a big-dog who knows how to do it right and get the most bang for your buck.
My forte' is definitely inventing products but if you pass me on the street holding a smoothie, be ready to hear about the Smoothie Press™!