It'll be pretty easy for target to prevent google from helping them, they can just decline to participate in the program. They are participants though, which should tell you something about how target actually feels about the program. And they don't lose any customer habit data, as customers still use their loyalty cards through Google Express.

Almost all of Google's profit right now is derived from B2B relationships. Providing services to other businesses is what they do. Yes, they make a good profit while they're doing it, but to suggest the business who are google's customers don't see any benefit from it is silly.