This is true, and your buying instruments (unless you always pay cash) or even your time of purchase/store choice will correlate out those three cards as all "you". We are very much creatures of habit and this is what Safeway and people like Target rely upon.

Now without the baby sitting co-op to randomize data I've offered my card to people ahead of me in line who don't have one, but again the gas rewards are changing that equation as well.