Publishers weigh the downsides to header bidding

Header bidding, the industry obsession du juor, has quickly become an enticing gambit for publishers looking to squeeze more revenue out of their inventory. But that doesn’t mean they’re willing to look past the tech’s faults.
With header bidding, publishers can combine demand for the inventory from both direct and indirect buyers in a single unified auction. This lets them make more money for their space because all demand partners are bidding at the same time.
But with that approach comes the risk of slowing down publishers’ pages. To implement header bidding, publishers add a line of Javascript to the header portion of their sites’ HTML. That can add more time to page-load, depending on how many header-bidding partners a publisher decides to work with.
http://digiday.com/publishers/publishers-header-bidding-downsides/