This is about to be a very big issue in the industry. Mike Baker at DataXu and I have been discussing this, and he has written a very thoughtful piece on the topic today:
"A Call for transparency"
I'm planning to write some more about this topic in the coming weeks. there is a big revolution going on in display, where finally the use of technology can transform display in the way that it did with search 10 years ago - with the result that spend on display will grow dramatically. Getting transparency about how a price is determined, and providing the right incentives for buyers to bid the full value of an impression (ie a second price auction, which can include a fixed floor) is critical if publishers want to benefit from the uplift in revenues that I believe someone like Criteo can provide.
More to come...