While online retailers like Amazon can collect and analyze an incredible amount of behavioral data via accounts, cookies, page-views and other web technologies, real world stores aren't so lucky. If you run in, pay cash, and run out, they're pretty much "blind". That is, until American fashion retailer, Nordstrom, decided to use our phones and their Wi-Fi signals to try and get in on the customer analytics game. Stephanie Clifford and Quentin Hardy writing for the New York Time:
Carrier IQ is software that manufacturers and/or carriers stealthily embed in mobile devices in order to collect everything from location to behavioral (usage) data. How much data they collect, and to what level of granularity, it's hard to tell, as is what they do with it both locally on the device and transmitted back to their servers.
Siri isn't a voice control system. Nobody uses those, and Apple wants something everybody will use. First, they value user experience, second they value differentiation from other platforms, and third, certain business models are predicated on having very large user bases. That's where the revenue streams become complex and the profit becomes really interesting.