[I'm Founder of isocket, the worlds largest marketplace for "premium" ad inventory]

This question assumes (perhaps wrongly) that 1) a SSP and an exchange platform are all that different and 2) publishers don't understand what SSPs do and are staying away from them due to ignorance.

It may be that some do understand and chose not to go that route. More and more premium publishers are improving their strategy by reducing the amount of inventory they make available in any of the remnant spot markets.

An SSP is basically an exchange of exchanges. Their job is to make the most out of your remnant inventory. An exchange has the same goal. And many of the exchanges expose your inventory through the same RTB pipes that an SSP would.

But just speaking about a situation where someone is defaulting to a single exchange out of ignorance, it could be any of the normal reasons that create early adopters vs late adopters, such as comfort in the known, perceived switchover costs, tradition, internal corporate bureaucracy, turf battles, people just not giving a crap, etc etc etc.

Also: Publisher's fear of channel conflict, price erosion, and data leakage are all completely valid - but sometimes publishers take this too far and make seemingly bad "ignorant" decisions based on fear and inaccurate info.

It's likely a classic case of control issues tied together with the mentality of "why pay a middle man".

In other words, the lack of transparency and control over your inventory scares them, and they believe they can sell it for more than you can...

It also might cannibalize their existing ad sales if their advertisers can go through the exchanges, as well as possibly hurt their brand equity, and create the impression that their ad inventory is worth less than they sell it for directly.

Honestly, after many years in the newspaper industry, you learn a few things. One of them is that many publishers are not technologically savvy. They've done it themselves for years, and aren't interested in paying an outside group a cut.

Simply put, its not intuitive to them. It's a much different business model than they have operated under. It takes time to understand, and many aren't willing to put in the time. Its also at times proven to not be as good as the claims say. There have been exchanges that promise big value and just end up serving cheap house ads that detract from the site and don't pay enough to make the accounting worthwhile.

Case studies are one thing, but get in front of publishers at the conferences and events. They like to here successes from other publishers, not sales people. Use your current clients to leverage new accounts.