It's easy to get caught up in the exciting new ideas behind start-ups, and big businesses attract attention because their size makes their impact impossible to ignore. But it might surprise you to know that the businesses that fall between those two categories—especially younger companies who are transitioning from start-up to major enterprise—play a key role in the economy.

Data on small-and-medium size businesses show that they drive economic growth and job expansion as they grow, and as they challenge larger competitors, they rely on innovation and technology to gain an advantage. Understanding the challenges that these firms face will be important rebuilding our economy after three years of recession and high unemployment.

We'll be looking within this universe to find the finalists for our new business index, the GOOD Company Project, based on the criteria for creativity, innovation and sustainability that we'll develop here at over the next few months. Stay tuned.