I see no reason why banks couldn't in principle do the same thing with purchasing data that carriers do with location data. There ought to be a distinction between private as in confidential and private as in "confined to multiple parties each of whom the data's subject knows of". Health data is so sensitive that it is protected under various laws and in most developed countries (the US being the largest exception) health care is run by the government rather than private companies. Unlike with health data, it is possible to avoid having banks and cell phone carriers collect data about you - always use cash and don't have a cell phone. In addition to being a very paranoid course of action, this is impractical for most especially when the privacy trade off is likely to be worth it in most cases. When those who already have your location data is considered, giving up your location data to Facebook oughtn't be too big of a stretch when they already know about birthdays, weddings, funerals, your friend network, etc. Retailers will already piece together private information about you from purchasing data that they can collect[1] and this is the position which apps seem to currently be in - neither Facebook nor Target want to make guesses at the rest of your private life but it is impractical for Target to make a request directly while Facebook has no qualms about doing so.

[1] http://www.forbes.com/sites/kashmirhill/2012/02/16/how-targe...