We often talk about the Internet, blogs, etc. as a medium uniquely impervious to standard corporate marketing tricks (e.g. "you can't buy authenticity") but I'm not so sure.

Scrappy-looking DIY-style flash ads (produced by corporate PR firms), astroturfed comments of an increasingly sophisticated variety, etc., may be expensive, but they can be developed and purchased.  I'd expect to see more of this as time goes on.  

Still better than ads on broadcast media, of course, because at least this kind of faux-populism is easier to detect...or is that really better?

Here's a darker vision for you:

1. People get sick of broadcast media as a news source and go to blogs, etc. (yay!)

2. Campaigns stop spending their PR dollars on broadcast ads (yay!) ...

3. ...and start spending those dollars on astroturfing online... (uhm)

4. ...and since authenticity is difficult and time-intensive to reproduce, these efforts become very, very, very expensive... (hrm)

5. ...Making the money race even more important for those who want to market on line than it was for those who market now in the broadcast setting. (uh-oh)

I don't have any particular reason to be confident that things play out as I've described above.  But I do think we should hesitate before we crow about our beloved medium's victories over corporate tactics.