I'm specialist in Sales excellence and had been worked for Monitor Deloitte for 7 years on this topic. Depending on your business, I'd suggest you not to define your client profile based on volume, geography size or segment. I'd rather to defening it based on purchase behavior(But it depends on your business). You are probably having hard time to identify the decision maker because of an inefficient segmentation criteria(ideal client) Once you review your segmentation, your will look for company contacts on you CRM, if you don't have one yet. do implement one. If there is no contact on your CRM, ask people of your company to find people from the prospect company (supposing you already have, at least, the company name) on linkedin, if not, ask you contacts, that you know have relationship with anyone on that company on linked in to introduce you to them. I hope it helps. If still you do not find anyone, let me know about your business so that I can go a little further on this topic and help you out.