Both. But generally the scales tip (strongly) in favor of intuition, precisely because quite often the window of opportunity to do something really great or meaningful exists precisely
because the data is scarce or completely lacking. In fact it is exactly this very kind of (justified) cognitive leap -- they (almost) telepathic ability to know what the customer needs or wants,
despite the data, and sometimes even despite their own stated desires -- that arguably is what defines and characterizes many of the most revolutionary innovations you can think of.
In fairness though, many "brilliant innovations" have also essentially been happy accidents, so one shouldn't get too big-headed about the value of intuition -- especially one's own.