Take a peek at the article from Wired Magazine (The Web is Dead). Look at the image at the top of the chart.
This is what we are seeing with classic catalog and e-mail marketing in the majority of my Multichannel Forensics projects ... the new channels come, but they don't fully replace the old channels, leaving business leaders in a bit of a pickle.
Fortunately, you can make a boatload of profit by cutting back on old-school advertising to customers who have made the transition to newer channels!
And by the way, read each viewpoint in the article ... please, read each viewpoint. An evolution that is going to swamp e-commerce is well articulated on each side of the spectrum in the article.