How do I market a great idea?

How do you test if there is a market for your business idea, and what are indicators of total market size and growth rate?

• All too often Entrepreneurs create a product or service around what they believe is a good idea only after to find that there is no market for it. As I read through the answers here, I see a common piece of advice "start with your family." Ok, great, my mom and grandmother need it (actually they bought it to see you succeed) but where do you go from there? What are some specific tactics that limited budget start-ups can use to get beyond the family but also reach farther than what one or two people can do "on foot?" Also, what are indicators during that validation that let you know what your total market will be? At what point did you decide to move forward? If you have specific examples of how many you reached, how much it cost, and out of that data how you decided to move forward, that would great if you wanted to share.

• Answer:

  Well for starters you can make an internet questionaire - for example you can make one with google for free and than advertise it on facebook to people you think are your possible buyers. You can also make a prototype of your product and carry it with you, so when you meet someone new you can ask for opinion. You can search for already existing data on market shares etc. on your national statistics institute, where the data shold be accessible for free.