Two things:
First, for the "loyalty cards" or whatever at major supermarkets, I try not to shop anywhere that would require such a thing, but if I must go there, I have a tactic. They will say "do you have your preferred card today?" and I say "no....." in a voice like I never heard of it and am intrigued. They will then say "well would you like one?" to which I say "yes, as long as I don't have to stick around and fill out anything" they will then give me a new card with a form to fill out and bring back next time. I get the discount, don't play their stupid game, and get the small thrill of costing them seven cents or whatever to waste a new card and form. [EDIT: then, of course, I throw the card and the paperwork away, and if I'm ever at that store again get a new one next time to throw away again. This wouldn't work if you go in often enough to be recognized by the employees.]
two - I'm not trying to be "holier than thou" or anything like that, cuz I am not for sure and am as guilty as anyone else in succumbing to convenience when I know better, but why were you at the Starbucks in B&N in the first place, lyra? Again, not trying to be smug or anything, but aren't there any locally owned bookstores or coffeeshops in your area? That's an honest question, because in many many areas there simply are not because they run the local guys out. I realize B&N is a very comfortable store, but I go there to read and sit in the comfy chairs, discover books then buy them elsewhere.
As an aside, and not trying to encourage anything illegal of course, but I used to work at B&N and know they have one of the most liberal shoplifting policies around. THis was in 2000 of course, but the policy then was that someone could obviously walk out with a stack of books, and we had to ask, like it was always our fault, "I'm so sorry, I must have forgotten to ring those up, can I help you?" and they could say "no, I'm leaving now" and we couldn't do anything, no police call or nothing. That may have changed though. Again, just FYI not encouraging anything. I do recommend spending money at local places anyway, though.
"Isolation, mis-education, and for the very clever there is looming liquidation." -Catch Twenty-Two "Bad Party"