Here is a great example of financial services turning their enormous data stores into customer useful information.
MasterCard Big Data division to build restaurant reviews site built on customer payment data | finextra
Cristobel von Walstrom, vice president, MasterCard Advisors Information Services says the site will run on purchasing behaviour, "that is, how people are voting for restaurants with their wallets".
She says that where people actually eat when they’re in their hometowns and when they’re travelling helps to provide a better insight into popular destinations than online review sites such as Yelp and TripAdvisor, which are too easily gamed.
Bankwatch 
It’s not a good idea. I go to a restaurant may not because it’s good, but because it’s close and cheap. I may also go to a restaurant only because I haven’t never been there.
But if its close to your home, and you go there x times per month that might mean something. Thats the key with, in this case, biggish data; the secret lies in the patterns that are uncovered.