Having run a services company for five years, I understand the need for differentiating yourself in the business. Simply speaking you need to differentiate yourself if you want a premium for your services. If what you are offering is available in plenty nobody wants to pay a premium.
Karthik at Purplepatch Services has a two page article on the same topic and it is available for download below. If you are in the services business or just curious about how services businesses can differentiate themselves, please take a moment to read the article. I am sure you will enjoy it
Services Marketing: Creating Differentiation in a Commodity Business (PDF, 2pages)
Have a great week ahead!