Constituo, Ergo Sum

I recently read Wired.com's article "You Tube vs. Boob Tube" which talks about some differences between TV (one-way) and online (two-way) media. In it is an interesting quote from some guy:

"If you aren't posting, you don't exist," says Rishad Tobaccowala, CEO of Denuo, a new media consultancy. "People say, 'I post, therefore I am.'"

I'm not sure I agree with such a generalization. I mean ...

I post to Blogspot, but mostly to share thoughts amongst those who already know I exist. I post to Flickr, again to share photos with the world, but again mainly to people I already know. I post to Apple Discussions, certainly not to show people I exist as a Mac user. And I post to DPReview, because I have questions in my mind that only specific people could probably answer with any certainty.

You? You post to exist?

(I'm posting now, only because I can't sleep. And I'm sure I'm not losing sleep because of this issue.)