Many years ago a colleague of mine told me that he thought I was more of a farmer than a hunter, which he said was fine. At the time I didn't agree because being a hunter sounded a lot more macho, active and plain fun.
With the benefit of hindsight I think he was probably right. The company I was repping for had the first product of its type running on low-cost PCs instead of expensive engineering workstations, so the sales team had spent most of their time in what I would call "rape and pillage mode". Sales people took orders and then moved on to the next prospect, like foxes in a hen-house they had so many targets they didn't know which way to turn.
When I joined I visited some major accounts who had bought the enterprise software a year or two previously and had never seen anyone since. Nobody had made sure that the tools were being used properly, nobody had asked if they needed more licences, worst of all no one had even collected any maintenance (then 15% of list price). So I did some pretty good business just fixing up the existing customers, selling them more licences, new tools and making sure the 15% was collected. Of course, I did my fair share of "hunting" as well... but not maximising your business out of existing customers is just plain dumb.
Many sales trainers stress the need to always ask satisfied customers for leads and referrals, but before you do that make sure you are maximising your sales into those existing customers. As a species we moved on from being hunter-gatherers to farmers about 10,000 years ago... there were good reasons for that!