From Steve Greenberg.
[Warning: Comic-inspired soapbox rant!]
Adjusting your shopping to save the world isn't always easy in America. I have tried to adjust my habits over the past two years so that as little of my money as possible goes to the forces of darkness. I joined the People's Food Coop and shop there when I can, but I think it defeats the purpose somewhat if I make a special trip there instead of just stopping in at the drug store on my way home from work (by bus or bike, usually). I won't shop at Wal-Mart for several reasons (sweat shop products, terrible labor practices, the relentless push for lower prices regardless of whom it hurts, it's a long drive for me, and it's basically a crowded, narrow-aisle, long-line miserable shopping experience, or it was two years ago when I last shopped there). I avoid Kroger because of their Kroger Plus discount card (go here to find out why grocery cards should be avoided). I try to buy less, buy local, and buy used if possible. But I still make a couple of trips a month out to Meijers, a huge combination grocery and department store chain headquartered in Michigan, to stock up on pop, cat food, and a few other things which are either unavailable or very expensive at the Coop. Meijers is non-union (and has fought to stay that way), and is very difficult to get to without using a car.
So I can't claim sainthood on the shopping angle, but I do think that it's important to consider what effect your purchases have on the rest of the world. If you need to save money, do it by shopping at a nearby store, even if it costs more, rather than driving 20 miles to some discount center. I'm always amazed when I hear people talk about driving 50 miles to some "outlet mall" so they can buy jeans or whatever for a little less than they could get them at the local K-Mart, but still for a lot more than they'd pay at the local thrift shop.
I probably need to read it again, but I highly recommend the book Affluenza as a great introduction to why and how people should both reduce and direct their shopping. As much as the advertisers would like you to believe it, having a huge house stuffed full of crap, with two or three new SUV's in the garage, will not improve the quality of your life. It does, however, have a negative impact on the lives of millions of others.
[End of comic-inspired soapbox rant.]