As regards the blog, many ex agency people who have moved on (and I include myself in this)have sold themselves on the “poacher turned gamekeeper” position. Perpetuating the need for advertisers to include ex agency people to understand and negotiate with the media agencies. This approach would tend to lock in the thinking that the negotiations are done based on CPM/CPPs and Rebate return. With digital, the agencies are actually more willing to put forwrd their planning/strategic skills.

As concerns Xaxis, it is interesting that WPP offers Xaxis or with more savy advertisers, it can offer more transparent solutions that are the property of the media agencies.
The question is what model will eventually win and when will Entities such as WPP start looking at the long term and the survival of the Media Agency system rather than short term and the fast buck.