larry doyle

Three things:

First, as Kruegdude suspected, the publishers will get to keep 100% of their advertising revenue if they sell it. (And 70% if Apple sells it) Adding several more million readers to their base rate will either increase what they can charge or make them much more attractive to advertisers. In addition, there are whole categories of advertisers who wouldn't advertise in a partiuclar magazine but would if was on an Apple platform. (fwiw, this is also currently the deal on Apple News)

In contrast,

Apple Music sellers get 70% of the pot, but no advertising revenue.

App developers also get 70% but have to split ad proceeds 70/30.

So Apple to Oranges to Blueberries.

Second, newspaper and magazine publishers get a worse cut when they sell their physical product through a third party (45/55 typically) Yes, those with an established online presence keep 100 percent of that revenue, but half of a likely much larger number  may be more attractive in terms of revenue and reach. 

Third, publishers who don't get on board risk losing readers as folks migrate to the Apple platform.

And then there's the WSJ story that's tanking AAPL this morning. An update?