“You know we can’t be the Purple Cow forever, ” said the voice on the phone. That was 4 days ago, and I can’t get the conversation out of my mind. In case you haven’t read it, “Purple Cow” is a book by celebrity marketer Seth Godin that says: “You’re either a purple Cow or you’re not. You’re either remarkable or invisible.” I like to think of myself as a purple cow. Well, if I don’t pick up my running mileage I’ll be a different kind of cow, but none one us wants to believe that we’re no longer remarkable or that we now work for a boring, invisible or irrelevant organization. Mr. Godin and others have written a lot about becoming a purple cow, but once we get our colorful cow status, how do we stay there? Very few have been able to sustain purple cow status for a…