It could mean working closely with a platform itself to beta test new products and features. Companies like CNN, The New York Times and The Washington Post have signed on as Facebook media partners and have collectively produced hundreds of Facebook Live broadcasts, for instance. Other brands such as The Wall Street Journal, Cosmopolitan, ESPN and more have teamed up with Snapchat to produce content for Snapchat Discover, Snapchat’s media portal.
It's been almost 2 1/2 years since this was published. I'm curious if the group has revisited this white paper to evaluate how these methods have worked over time.
Prima fascia evidence would indicate that most major publications that have gone all-in on some of these experiments have only lost out on them following the pivots that social silos have made since. A good example is the large number of publishers that went in on Facebook video related products only to have Facebook completely abandon them. It's not a partnership if the publication has no recourse when the social platform abandons them.
I seem to recall that several online pubflishers were essentially forced to completely shutter following social platforms pivoting unexpectedly.