Announcing Entrepreneur 360, Our Index of the Most Entrepreneurial CompaniesThe Entrepreneur 360 Performance Index takes a holistic approach to ranking companies and quantifying qualitative aspects of business.

Entrepreneurship is like a marathon, and not just because it isn't a sprint. Think of it: Thousands of companies set out for an achingly long test of their strategy, their preparation and, most of all, their ability to endure. For all companies, the start is the same—everyone is equal before the starting gun goes off. But soon some break free of the masses and move ahead; others fall behind.

We at Entrepreneur Media celebrate this race, supporting the nobility of the struggle entrepreneurs face each day. That's why I'm pleased to announce that this year we will launch the Entrepreneur 360™ Performance Index, a study of the best American entrepreneurial companies.