What is Real CGM?

What exactly is real CGM?  This is the topic of my upcoming ClickZ piece, but darn if Jackie Huba didn't raise this critically important question first...just minutes ago.  It's a great question to think about in the context of the Chevy Tahoe "create an ad" program.  Say's Jackie: "Calling it CGM is rather generous...It's really a game. To wit: Participants submit their finished commercials to win prizes."  Oh, and to top it all off, she YouTubes (yes, I'm creating a verb) her own piece of CGM that takes a less flattering brand ride.  Joe Jaffe, in another blog post, also asks a few really good questions about the "constricting" nature of the promotion rules. As the term "engagement" deepens into our everyday marketing vocabulary (this will be a huge theme at next week's Advertising Research Foundation (ARF) conference,) expect marketers to begin pushing the limits of consumer "participation" or so-called "conversation."  We're already seeing this in the corporate blog space? Will they co-opt or nurture real conversations?  Will they promote or taint authentic brand evangelism?  Will they spoil that incredible, trusted "media" know as CGM?   These are precisely the questions we should all be asking and debating.