Ways of encouraging companies to participate in survey for my doctoral reseach I am a doctoral candidate in Business Administration, researching the use of ERP (Enterprise Resource Planning) programs in companies. When I have explained my research to system administrators, the usual response is that it is an interesting subject. Despite the use of social media such as LinkedIn, a user group forum and direct mailing system administrators, very few companies have consented to participate in the research. 

The research will be implemented via user questionnaires. In my opinion, very little time is actually required to complete the questionnaire (obviously I'm biased) and point out in the covering letter about the research that completing the questionnaire requires only about ten minutes. Of those companies who bothered to reply, almost all have stated that participating would require too much time.  

Does anyone have any suggestions how I might encourage companies to participate? I know that basically I am asking them for something and not giving anything back in return.
From what you've described, you haven't done much, if anything, to provide a compelling argument for companies to participate in your research. Even though it doesn't, from your point of view, take much time or effort, it does take time and effort, both of which cost money. 

If you're talking to a company that has 300 employees. You say it takes 10 minutes. Now multiply that by the number of participants and you have 3000 minutes or 50 person-hours. Then multiply that by the labor cost, say $80/hr (you have to consider the entire cost of the employee's time; salary, benefits AND the missed opportunity cost of NOT doing what something that would make the company money) that's $4000 for your 10 minute survey. 

You need to think about what you can offer in return for their $4000 and sell it. Access to your findings? What would you offer them if you were asking for that much money to fund your research?