If someone asked you to go to a white board and sketch out a day in the life of your customer, what would you draw?

If you've given half a thought to your market, you no doubt have some idea. Maybe you know a general age range, urban v. suburban, a sense of the type of jobs your archetypical customer might have. Is that enough?

Not if you want to satisfy serial-entrepreneur turned professor Steve Blank, who suggested this exercise recently in a Kauffman Founders School video. "If all you could do is well, they're 40 to 45 and they work in these kinds of companies, you really don't quite understand the entire Gestalt of their life. You need to find out a bit more," he insists.

How much more? Way more than you probably think.

A day in the life of your customer

What you need to be doing is "actually getting out of the building and trying to understand something which I call the day in the life of the customer," he explains. "You need to know everything about that customer. What are these people doing from the minute they get up to when they go to bed. And more importantly where are they living, what are they driving, what do they read in the morning what blogs, what newspapers, what do they listen to. When they get to work, what's on their computer, what kind of apps, what kind of computer are they using, what do they buy."

What's the function of this Cheerios vs. Coco Puffs level of granularity? Efficient targeting of your customer acquisition efforts, according to Blank.

"While you might think some of this stuff is extraneous, a good number of these things might actually be useful later if you want to target them outside of the office or in their homes, etc. If you don't know all the characteristics of their life, you're going to be missing some opportunities. Or you might be missing an opportunity that your competitors just haven't figured out," he warns.

How to find out

If you're early in the process of building your business and your sense of your customers' daily habits is hazy at best, don't fret too much. While Blank has firm words for entrepreneurs who aren't interested in learning about the minutiae of their customers' daily lives, he reassures the curious but confused that acquiring the necessary knowledge should be a trial-and-error process.

He suggests "running a series of experiments" to test your informed guesses about how your customers spend their days. "If we believe that our customers are actually youth, 15 to 25 in urban areas for example, we would try some acquisition programs with the either keywords targeted to urban youth or we'd run ads in places where we think they might be reading, watching or living. And we would see if actually that is who our customers are," he explains.

As long as you keep your experiments cheap and quick, failure is as valuable as success, teaching you important lessons and prompting you to try again.

Want to hear much more of Blank's wisdom on how you should and should not go about understanding and acquiring customers? Check out the complete nine-minute video.

Do you know what your customers eat for breakfast?