A Good Product Is Not the Same as a Successful Business — Here's How to Turn One Into the Other "If you build it, they will come" is terrible advice for startups. Here's why.

"If you build it, they will come."

That's the famous phrase whispered by mysterious, disembodied voices to Ray Kinsella, an Iowa farmer played by Kevin Costner in the 1989 film "Field of Dreams," urging him to build a baseball diamond in his cornfield. ("They," in this case, refers to the spirits of dead legendary baseball players.)

While this may have been great advice for Ray, this wisdom does not apply to starting a business. In the startup world, building a product — even a really good one — is not a guarantee of success.