The markup through an exchange can be considerable and can significantly eat into margins. Some advertisers seem unconcerned about this fact though, and appear to be more interested in just making the buy rather than maximizing profits. Even after they are approached by the publisher and informed how much cheaper they could buy the inventory if they bought it directly, they still decide to buy through the exchange.
Buying programmatically and working directly with a publisher do not have to be a choice of one or the other. The option of private marketplaces allow advertisers and publishers to work together in an environment that can be direct yet programmatic at the same time. Private marketplaces can be a win win for both parties as advertisers can get first shot at premium inventory programmatically without having to pay a higher margin through an exchange and publishers are able to work directly with the advertiser and potentially receive a higher fill rate and CPM.
If publishers are selling any of their supply through an exchange they should inquire if they can receive reporting on which advertisers are buying their inventory through it. Not all exchanges offer this transparency but some do. Once publishers have this data they should review it to learn who is buying their inventory directly, and then reach out to those advertisers to see if they can work with them directly. Many advertisers do not know which publishers they are buying from in an exchange and would be open to working with them directly if the quality and amount of inventory was significant enough.
The online ad industry is evolving quickly and more and more inventory can now be bought programmatically. No one will argue the benefits of that, but it should not cause publishers and advertisers to become lazy. There are still huge revenue opportunities for both parties if they take the time to analyze their data and maximize the potential relationships. The programmatic environment should not be an excuse for both parties to work less hard, but instead to use it to their advantage to identify opportunities and maximize revenue.