I’m going to bang on until I’m blue in the face about this subject, because I will never, ever understand why so few companies survey their customers before making decisions which will affect them. Surveys are fast, and if you already have your customers’ email addresses – free. Yes, of course there are caveats about the responses (you only get them from people who like filling in surveys, and these might not be representative of your customer base as a whole) but the results are infinitely better than just going on a hunch.
Make Marketing Decisions by Using Surveys on the B2B Lead Blog discusses the whole topic and links to two online survey tools which can get you going today. I know of a company which once surveyed its customers in the middle of a marketing meeting, and had results back before the meeting was over. How cool is that?