Howard Stern has lost most of his audience. I’m not a big fan of his. I like public discussion of sex that is more interesting and productive than Howard offers. But I’m not above learning from him, and how can you not learn a lesson or two from a guy who has lost almost 11 million of his12 million listeners in just a few months?

Stern bet that his audience was so loyal that they would pay $13 a month to listen to him on satellite. Inside Radio reports today that most of Stern’s listeners are just plain too lazy to make the switch. (Though 13% don’t want to pay the extra fee.) The findings of this survey are consistent with the conventional wisdom that 80% of lost customers were not actually unhappy with what they were getting.

Each of us takes little gambles with our customer base all the time. Yesterday, for example, I told someone that I was changing our project specifications a little bit. I moved away from her vision and closer to my own. I made a bet that she likes working with me enough to put up with my change.

In this vein, an editor once told me, when I turned in a column late two weeks in a row, “People who write as well as you can be late. You just need to keep writing well.” That worked for a while, but then I really pushed his limits and he fired me. In this sense, I have empathy for Howard that he overestimated loyalty. Today I make more conservative estimates, and I bet Howard would do the same, if he could.

Once we all admit that we are all marketers, then we’re more humble about loyalty. Then we’re more careful to really get to know your clients and what matters to them — be they radio listeners, editors, consumer purchasers, or the guy in the cubicle next to you.

Howard Stern overestimated how dependent his listeners were on him, but perhaps he underestimated how beholden individual radio stations were to him. The trick, as a marketer, is to find out whose business is most dependent on you, and who you are most dependent on. Then you know where you have room to wiggle.