Here are the top 5 reasons to hire a business consultant.

1. There does not appear to be an answer. You have spent countless hours researching and analyzing and still have not come up with the solution to increasing your revenue stream or reducing your productivity associated costs. Often a business consultant can come in with a new set of eyes that can identify new opportunities for you.
2. You don't want to be the bearer of bad news. A consultant will not recognize the relationships that exist in your environment. He or she will strictly be looking at your business model and making suggestions based on fact. Those suggestions may include terminating or reducing the pay of individuals that have worked for you for a long time, but those reductions may save your business and the jobs of many.
3. The problem that needs fixed most is not your specialty. You may not have the training or experience in a segment of your business that requires attention. For example you may not have a web presence that is excluding your company from web searches looking for your product. A consultant can identify the proper resources for you or assist you directly.
4. Training. The members of your organization can greatly benefit from a new training structure introducing new tools for productivity or cost control. 
5. Recruiting and Staffing. Many times the solution is as simple as recruiting and hiring talent to your organization. A top sales producer that immediately boosts company revenues can very quickly cure a failing bottom line.