'Accidental Entrepreneurs' -- When a Personal Mission Morphs into a Big Business Jessica Alba just wanted a better, nontoxic product to bathe her baby. Today, her company is worth more than $1.7 billion.

Some of the most successful and inspirational entrepreneurs never set out with the goal of running a large company or employing scores of people. Many are simply men and women motivated to develop solutions to a problem they're facing.

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Then they discover that they're not the only ones with that need -- and, lo, a successful business is born.

Sometimes dubbed "accidental entrepreneurs," these business owners have other names, as well. The Ewing Marion Kauffman Foundation, for instance, calls them "user entrepreneurs" in its research, which has found that this group has launched more than 46 percent of startups lasting five or more years -- even though they're responsible for just 10.7 percent of U.S. startups overall.

That's an impressive success rate.

Nor are accidental entrepreneurs necessarily motivated by financial reasons. Many, at first, are just looking to cover their costs or pay the bills. But, being so personally invested in solving a problem, these entrepreneurs often have the tenacity and drive to see their vision to fruition.

In short, entrepreneurs who set out to solve a problem they've personally experienced may have an advantage over entrepreneurs just looking to make a buck.

Who are these user entrepreneurs? A great example, is Sara Blakely, the founder of the hosiery company Spanx. Blakely launched Spanx after searching for a solution to improve the way she looked in a pair of her cream-colored pants. "I'd never worked in fashion or retail," she jassaid. "I just needed an undergarment that didn't exist."

Blakely set out to make sure that undergarment did exist. And in 2012, she became the youngest self-made woman to make the Forbes Billionaire list.

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Melissa Kieling is another accidental entrepreneur. Single mom-turned businesswoman, Kieling founded PackIt, which makes foldable, freezable lunch bags and has been named one of the fastest growing privately held companies.

Kieling -- who at one point had just $13 in her checking account -- has said she started PackIt at her kitchen table after years of searching for ways to keep the fresh healthy lunches she packed for her kids from turning to tepid mush by lunchtime.

As Kieling and Blakely show, it's more than possible to turn a personal mission into a successful business. So, if you've got your own Big Idea, here are a few pieces of advice to help you with your own journey.

1. Start with a budget and realistic assumptions.

While faith and optimism are essential qualities for any entrepreneur, you will want to temper your enthusiasm with an ounce of reality. If you were planning on driving from New York to California, you would probably want some sense of how long it would take and what route you'd use. Similarly, you need to plan for your business, with a forecast and budget.

Ask yourself the following questions and make some realistic assumptions:

• How much should I charge for your product or service?
• How much might I realistically sell next year?
• How much will it cost to manufacture the product?
• Do I need to hire employees next year? How many?
• Do I need to pay myself for the next year? How will I take care of daily expenses and things like my mortgage?

In addition, you should hire a good accountant early on. He or she will make sure you stay on track and don't spend money you don't have. Without some "tough love" from my own accountant a few years ago, I'm not sure my business would be around today.

2. Don't take 'no' for an answer.

Whenever you're working on a new business or product, you will inevitably hear people say your idea won't work. You'll be rejected by potential investors, partners and suppliers. But, "no" can't be the final word: If a door is slammed in your face, find a window.

When Jessica Alba couldn't find non-toxic bath products for her baby, she decided to make them herself. But when she began pitching her idea, she ran into several roadblocks. "People told me not to bother going up against the huge, established multi-national corporations that were selling these products. People also thought my idea already existed," Alba recalled while speaking at the University of Southern California.

Certain that other parents shared her need for better, non-toxic products, this accidental entrepreneur never gave up. She did more market research, honed her business plan and turned to Brian Lee, a serial entrepreneur she had targeted for his ecommerce expertise. Lee, who at first turned her down, signed on the second time around and became one of the co-founders of The Honest Company (now worth over $1.7 billion).

3. Get your legal foundation in order.

Even if you didn't originally start your business to make millions, you still need to take your legal responsibilities seriously. Check with your local county office to find out what permits and licenses are required for your venture. Also consider creating a formal business structure, such as a corporation or LLC, in order to separate your personal assets from your business.

If you're developing a new product idea, protect it by applying for a provisional patent as early as possible. Later on (perhaps after you've secured financing), you can hire an attorney to help you with your full utility patent application.

4. Broaden your focus.

One potential risk for "user entrepreneurs" is that they may become too narrowly focused on solving a specific personal need. It's good to use your own needs as a template for building a product and company, but you also need to be aware of what's happening around you and what others are experiencing as well.

In her book Reinventing the Entrepreneur, Maryellen Tribby writes about a woman who created an entire business around helping other women survive a divorce, but then expanded to topics like how to date and maintain a relationship after divorce, and how to manage money as a divorced parent, etc.

As Tribby explained, "As the people in your market grow, you grow and mature with them. If you're too narrowly focused on a topic, such as how to survive a divorce and only how to survive a divorce, guess what? You may have the greatest information in the world, but once [your potential customers] read it, they're done with you."

4. Keep that initial fire burning strong.

Zig Ziglar has written similar thoughts on entrepreneurship and motivation: "People often say that motivation doesn't last," he's written. "Well, neither does bathing; that's why we recommend it daily."

Caught up in the daily grind and stresses of running a business, you may find that you lose that initial spark that pushed you to start a business in the first place. But the most meaningful things in life require a continued effort.

When your own motivation is low, spend a few minutes remembering your past successes. Think about the process you went through, how it felt to reach your goal or make an important decision. Think about the positive impact you're having on the world around you. Let those good feelings wash over you and refuel your motivation.

The beautiful thing about running a successful business is how it lets you scale your impact. You may have started out in order to help your own situation, but your vision and dedication can make a difference literally to thousands, even millions, of people's lives.

And there's nothing "accidental" about that.

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