Answer:
They help you find unbiased information about the product’s actual performance.
Step-by-step explanation:
We all have a tendency to highlight our good actions and successes, while hiding our bad actions or failures. The same happens within a business, upper management usually gets the reports with all the wonderful statistics about how great the company's products are and how good our customer service is. Reports containing information about failures or customers' complaints are usually extremely short and not very detailed compared to the essays highlighting success.
So if you want to research information about how good or bad a product or service is, you must look outside. It is plain common sense, no employee likes to put his/her job at risk by writing about how bad the company's products are. That is why independent consultants are hired.