Where am I going wrong?

I run a small company that specialises in editing and proofreading academic documents such as theses and research reports. Ive identified my niche market and done extensive research on it, including using focus groups etc. I advertise on Wits intranet and in their student newspaper, have approached every tertiary institution in the country (with no response), handed out flyers at student bashes, and have also advertised for student reps who will earn a good commission on each thesis they bring me for editing (also with no response (don’t they need the money?). I also advertise on 94.7’s website, iafrica, news24 and this website (classified section). Despite all this, business is slow, slow, slow! I have brilliant references from past clients, so I know its not the quality of my work! Where am I going wrong?