Microsoft is a great example of company that has succeeded by execution. They’ve rarely been first to market with any of their products, but they’ve successfully brought them to market, figured out how to improve them, and introduce them again and again. This is the approach that puts you in the Fortune 500.

Why do entrepreneurs believe so fervently in the myth that they need to be first to market with a never-before-seen innovation? Because that’s what they’re told in business school. The problem with this piece of wisdom is that it encourages business leaders to wait until the mythical breakthrough business idea is fully formed.

This myth is fed by the public perception of groundbreaking companies as having come out of nowhere to rock the world. But companies like Facebook rarely, if ever, spring into being with no antecedents: MySpace and Friendster were in the market first, but Facebook did social networking better than anyone else had done before. Google wasn’t the first search engine ever; AltaVista probably deserves that title. But Google advanced the search experience to the point that we all believe they were the breakthrough innovator.

The point I’m making here is that you don’t need to have the breakthrough vision to launch your company – you need to have breakthrough execution. Launch your company even if your concept is similar to someone else’s idea, and figure how you will change the business model.

When you stall your entry into the market, you run the risk of getting outrun by competition – who’ll have gathered valuable on-the-ground information and solved problems before you’ve even planned your launch party. At a certain point, the ecosystem around your market will have become so strong that consumers will not be willing to accept a new entry. For example, anyone who launches a Facebook-style social network right now will have to hope that people are willing to totally rebuild their friend networks from the ground up.

On the other hand, if you can tweak this idea for a new market – for instance, a social network that specifically serves the healthcare community – you can launch without an entirely new concept. Or you can go to a locale where you’re not first in the market, but where there is greater potential to become a player.

In other words, you can be first to market in Seattle with widget XYZ, where there’s only a moderate interest and market potential for your product. Or you can be tenth to market in Tulsa where there’s a far greater need for widget XYZ, giving you plenty of room to gain customer share. Here’s how to position yourself for entrepreneurial success without playing the waiting game.

Follow your heart – but use your head. As an entrepreneur, you should always develop businesses that you are passionate about, since that enthusiasm will keep you pushing ahead when times are tough. But that doesn’t mean you can’t think rationally about how to apply what a competitor is doing to a different market segment or locale.

Listen to the market, and tweak as needed. The reason for launching sooner rather than later is to gather feedback from initial customers, so that you can redesign or retool as needed. Without this early feedback, you can only guess as to what customers are willing to pay for.

Don’t wallow in brainstorming. Time spent fiddling with a business plan or filling up whiteboards with ideas is time that you could spend actually launching your business and seeing if the idea floats. If it’s real, you get solid feedback, instead of the imaginary “what if” scenarios you dream up in a conference room.

Launch early enough that you’re partially embarrassed by your first product release. Entrepreneurs are likely to be somewhat off-base about their first launch and what features customers really want, but they won’t make a product better until people are actually using it. LinkedIn founder Reid Hoffman says that his co-founders wanted to delay launch until they introduced the professional social network’s “contact finder” feature, but it turns out it wasn’t necessary — eight years later, LinkedIn still hasn’t added that feature.

Be your own worst nightmare. Once you do have that toehold in the market, ask yourself how you would outflank your company if you were a competitor. Constantly out-innovate yourself, and determine how to make your product offerings obsolete with each iteration.

Follow Naveen Jain on Twitter: www.twitter.com/Naveen_Jain_CEO