I worked on this 3 years ago with MC. There are 2 major hurdles. The first is legal. The Gramm, Leach, Bliley Act prohibits MC & Visa (and issuers) from sharing transaction data with a third party (we think we figured a way around this). Card linked offers get by this by presenting the offers on the mobile and online banking interfaces of customers that have opted in...much less desirable than presenting offers (based on their spending data) to customers when they are on the merchants website shopping.

The second is technology. Being able to provide relevant spending data to real time bidding and personalization platforms on merchant websites and being used for online advertising, in milliseconds, requires advanced technology. We were programming in Clojure and using a Datomic database.

Either way MC, for reasons I won't reveal here, in my opinion, has a an advantage over Visa on executing this.