Marketing is any activity that exposes you to your audience.

I talk to a lot of businesses that don't know what they're doing to market themselves. Actually, scratch that. I talk to a lot of businesses who can't tell me what marketing is in the first place. To their minds, it has something to do with social media or videos or advertising or calling people to hiring more sales folks or writing blog posts but they're just not entirely sure...

...and that's why they're blowing it.
It's not that their marketing isn't working, it's that they don't really understand what marketing is, or how it works, or why it works, or anything else. It's pure chaos, and it's pure failure just waiting to happen.

From our column on Inc.com