I think you should do SMO, I think Facebook is best option to promote any kind of product. One of the main benefit of Facebook is you can update your Business services to a particular category of your required customers.
SMO is the best option to do at free of cost. PPC is more effective if you want to spend bucks. Try to use as most of Social Media sites as most you can. I have also a better option rahtar than PPC. If you really want to spend bucks then spend it on Branding. Right Now, many SEO companies are starting Branding and which creates a vast reputation to your site.