Rarely is a great company based on one great idea. Typically, the initial idea you have for a company gets transformed significantly over time. For example, PayPal initially offered a service that allowed one Palm Pilot to pay another. When customers told the company they really wanted the ability to pay others online, PayPal changed routes and built a billion-dollar business.

Jake Turcotte/The Christian Science Monitor
Your great idea is a starting point – not the end point – of starting a business.