You're losing a lot of business to your competition if you aren't automatically answering that question every time you communicate with a prospective customer.
The answer to the question, "Why should I do business with you?", is called your Unique Selling Proposition or "USP". It's the specific benefit I get by doing business with YOU... a compelling reason to do business with YOU instead of with your competition. Your USP is a powerful tool for positioning your business in the minds of your prospects and customers. Without it you're just another source among many for the product, service or opportunity you offer.
If you don't already know your USP, here is a quick way to find it. Make a list of all the benefits you offer to your customers. Write down everything you can think of. Is there one major benefit on the list your competition doesn't offer? If the answer is "yes", that's your USP. If the answer is "no", you probably don't have one.
Don't worry if you don't have a USP. You'll just have to create one. How? By adding something to your business you're not already doing. Put yourself in your customer's shoes. If you were the prospect being approached, what would it take to get your attention? What can you add to your business that your competition doesn't offer? Make that your USP.
Here are a few examples of some USP statements to help stimulate your thinking...
Private Investigator: "We either find the person for a fixed fee or refund every penny of the client's money"
Resume Service: "Survey: 79% of our clients acquire higher paying positions"
Security Systems Installer: "Security systems designed and built by a policeman"
Plumber: "One of our 65 completely stocked and radio dispatched service trucks is in your neighborhood now"
Once you've identified your USP, convert it into a brief statement and integrate that statement into everything you do. Make it the central theme in all of your advertising. Decide on a strong USP for your business. Use it continuously in everything you do. Never let it escape the minds of your prospects and customers and you'll see your business grow far ahead of your nearest competitor.