And I'll show what's wrong with both of these "things"
I'm scared. Scared for my privacy, scared for the simple act of doing something without anyone knowing. Scared that I will no longer be able to tell my real life friends "Hey, guess what I did today?", because they'll know because they would have looked at my Facebook profile and seen what I was doing that day.
This is too much, we're getting too connected in the bad way. The potential-for-stalking way.
This thing does have a place, and it's got to do with buying shite:
Step 1: You sign up to a list which tells you when/where you get discounts
Step 2: You choose your interests and preferences for categories that you want discounts for
Step 3: When you're out, the discount site uses the GPS in your phone to tell you "hey dood, there is a discount for chocolate salty balls 25m from where your standing right now. Show them this barcode to receive 15% off"
Step 4: And if credit card providers are smart, they'll jump on now, create alliances with certain stores and if you are a holder of credit card X, you are eligible to receive discounts from all of X's partners which X coordinates. Sweet, hey?