Survey after survey has shown that the number-one thing entrepreneurs fail to do is survey the marketplace to determine if there is interest in their ideas.
I can't tell you the number of phone calls I get from people who tell me their friends and relatives think their idea is a winner. That your Aunt Betty in Wisconsin thinks your idea is fabulous isn't enough. You need to get more objective opinions before proceeding further. These opinions will help determine your eventual target market and potential sales volume.
By not surveying the marketplace, many people unfortunately lose control of their idea, lead the idea in a doomed direction, or, worse, fall victim to one of the numerous unscrupulous "invention marketing" organizations that take your money and give you little, if anything, in return. (Beware: Anyone who tells you early on that your idea is a guaranteed success is probably being overly supportive or trying to rip you off.)