In reply to Philip Cohen.

Read MasterCard's latest fee release on MDES. They will charge for token use...there will be a fee to the issuer and the acquirer. Different than interchange and rates, but acquirers and issuers are going to be charged by MasterCard to use MDES. Visa hasn't come out with the same sort of logic. As far as discount and interchange, the category for NFC is still cardholder present rates and InApp is preferred ecom rates. What the issuers pay to Apple (the 15 bps) is between the issuer and Apple. You should assume that the people with direct knowledge of those deals are not allowed to comment on those deals.
But all of this is separate from Apple - even though Apple Pay is really EMVCo tokenization. Merchants and acquirers aren't paying Apple anything for this service.
As far as why issuers would pay - they'll pay to maintain top of wallet with affluent consumers. Apple consumers are more likely to spend...and so as an issuer you want to be there.
On the Visa Checkout and MasterPass comment - again, issuers will pay to be in the MasterPass wallet...it's not free. Use of MDES incurs a fee. Visa hasn't said what they're charging...or if they're charging. But again, issuers will pay because they'd rather be in the wallet than not.