If a card falls...

I went to the store this afternoon to get some bottled water and some stuff for dinner. While waiting in line at the checkout, I noticed this little old lady ahead of me. She picked up a magazine off the rack, and one of those annoying 'subscription cards' fell out onto the floor. She looked down, noticed it laying there, seemed to give it a moment of thought, then ignored it and went on about her business.
At first, I thought "Geez, how irresponsible." Then I thought, "Y'know, I really hate those little cards and I doubt I'd bend over to pick one up either."
And I kept vacillating between the two opinions. On one hand, those cards are nothing but a nuisance, and a magazine with ONE missing can hardly be considered damaged merchandise. On the other hand, someone's eventually got to pick that card up, and I feel sorry for the store employee who has to be the one to do it. Yet, isn't that partly what they're paid for...?
And I have to admit my actions would probably depend on whether someone was watching. If no one was there, I'd be much more likely to let the card remain on the floor. If someone was behind me noticing my response, I'd be more likely to make the effort to appear responsible and pick up the 'trash'. Yet this little old lady didn't seem to care whether I was watching or not. She left the card there, with no apologies.
How about you? What would you have done?