How much to listen to customers?

One item I've been perplexed with strategically lately is not whether to listen to current customers but rather how much to listen to current customers.   The reasons to listen to current cusomers are obvious. It's business 101. But the reasons to temper the amount one listens to current customes are:

  1. There may be business rationale (i.e. market size, competition, margin etc) for going in a direction that conflicts with what customers would say
  2. What customers say and do are often different things. Customers don't put their answers to survey questions into context for you....and vice versa.  Customer feedback typically comes in the form of interviews and surveys....and that's helpful, but isn't that useful in answering fundamental strategic questions.