John Rampton over on Forbes.com has written a handy guide to creating your own content marketing business. He covers the following main points:

• Clearly define your niche
  
• Offer a range of services for every budget
  
• Consider taking the consulting path
  
• Market your own business with content
  
• Decide whether to hire in-house or utilize freelancers
  
• Build out your case studies and testimonials
  
• Differentiate yourself by collecting your own market data and research
  

If you're looking at specialising in content marketing, or offering it as an add-on to your current services, this article is a great starting point.