Trust your data, not your gut
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There's a bunch of research that suggests that our unconscious mind is much better at making sense out of a large number of contradictory signals than our conscious mind is. If you blindly follow the data, you'll end up following whichever piece of data was in your mind at the time you made the decision. Instead, you want to absorb that data, let it affect your gut reactions, and then make a decision based on everything you know about the product and market.
You do, of course, have to "prime the pump" by seeking out information, particularly information that contradicts the assumptions you already hold. But you want to incorporate that information into everything else you know, not immediately take action because of it.
I specialize in marketing, and frequently I have to commit large sums of money to media buys without any hard data about whether the traffic will convert or not(beyond basic, vague demographic info). I have to make a gut decision about the quality of traffic coming from a particular site/campaign, and then wait for conversion data to come in before finding out if I was right.
I found that as I gained more experience doing this, and my unconscious absorbed more and more data from past campaigns, I got a lot better at those gut decisions.
Now, most of the time, I can look at any site or traffic source and estimate somewhat accurately how valuable that traffic is and make a quick gut decision about whether it's worth investing in. In the absence of hard data, being able to make these quick gut decisions is invaluable.
An important point in this. Where possible, allow your gut/subconscious some time to integrate what's been taken in.
Being in general proactive can help in this regard. You aren't rushing at the last minute to assimilate everything.
There's the balance, you don't have to turn everything in as far ahead of deadline/necessity as possible. And with respect to that, often conditions and requirements change anyway, requiring adjustment. But by tuning in early, you give your whole self time and space to work on the problem. That magical "intuition" is then more likely to show up when it's needed.
EDIT: Hope I'm not being too redundant with my comment.