This is part of what I think Jesus is getting at when he says we are the light of the world (Matt 5.14-16)- you are witnesses whether you want to be or not. Can a city on a hill be hidden? No, of course not! What we do reflects him always so we should be self-conscious about how the world sees him through us.

Isn't marketing the same thing- making sure we present our "product" accurately and positively?

I would urge you all to listen to this teaching by Rob Bell. He speaks very powerfully about this issue. Although not strictly about marketing, I do feel the most powerful aspect of marketing is not how you present yourself but actually what you do/don't do.

http://digg.com/podcasts/Mars_Hill_Bible_Church/375235

Not being in action when action is called for is just as dangerous as the wrong action.

It's a beautiful thing.

Does this also work for people who get upset when others judge them by their appearance?

I had a communications professor in college that used to say, "you can't not communicate." After all these years that has stuck with me, and not just because of the bad grammar. Having been a pastor and now a marketing firm executive I've seen this played out time and time again. If you don't tell people what you want them to know they'll fill in whatever blanks they can find and come to their own conclusions. As church marketers we can't allow that to happen.