Before 2000, media was seen as straightforward. There were four channels, print, radio, TV and outdoor. In order to communicate to an audience, you had to craft your message, then syndicate it by buying space on those channels. Now, in the digital age, the media landscape has become a vast, convoluted minefield. We’ve asked three of the most eloquent practitioners in that terrain to articulate their own significant experience digging the trenches and laying the groundwork.