How do you go about evaluating whether or not consumers will support your idea? You need to take into account complex variables, including the most unpredictable variable of them all: human behavior. This variable turned bell bottoms, Mood Rings and Hula Hoops into huge successes.
This task isn't easy (or consistent), but honestly evaluating your product against general, industry, market and product criteria will help determine whether it has a good chance of success.
Is your idea legal?
What is its environmental impact?
Is it safe?
Is it high quality?
Will it have wide social acceptance?
Will it have any negative impact?
Who is your competition?
Does your product require the assistance of existing products?
Is there just one product or a line of products?
Will pricing be competitive?
Does your idea fit into a trend?
Is there a need for it?
Is it seasonal?
Is it a fad, or does it have long-term value?
Who will buy it?
Does it need instructions?
How much will it cost to get your idea to market?
Does it require service or maintenance?
Is there a warranty?
Does it need packaging?
Is it the simplest and most attractive it can be?