The math simply doesn't work for publishers. The "transparency premium" today is approx 5-10X. Specifically, publishers sell their inventory for 5-10X the price they get through exchange-like channels. Sometimes the premium is significantly higher.

In my experience, clients are rarely willing to pay 5-10X the price to ensure transparency. Similarly our models can rarely justify that premium based on the added info we can glean from a known site versus an anonymous ID.

I think the real education process should be convincing advertisers:
1) The premium for site-level transparency (often) isn't worth it. Get comfortable that you're getting a great discount in return for the lack of transparency.
2) We're putting your message in a safe environment and have controls in place to minimize brand risk.

I'm not trying to discount the thinking above, which is great. But I don't think we'll all grow fast enough by waiting for the publishers to get comfortable with transparency.

N.B. I commented before reading Joanna O'Connell's post: Redefining Transparency. I think she's spot on and bridging the gap in a way that's educated by lots of "in the trenches" thinking at Razorfish. Worth a read!