Thanks, that's a valid point!

I've also seen Rand's great whiteboard Friday post. And one issue comes to mind:

If the pages used for PPC campaigns have the same intent as the generic, with relevant actions/conversions for the customer, shouldn't these signals be available to Google? Hence rel=canonical would be the best solution? Or?...

Rand did not mention a case like this as I recall, and I guess I'm not the only one with campaign pages...

Thanks for replying to this! It's an interesting issue for my client.