If you can't afford it, then get it for free

— -- Maybe there is no such thing as a free lunch. Or trip. Or skin cream.

But there often isn't very much expected of you from retailers and other companies that offer stuff for free, which can be all the more enticing in these trying economic times. The trick is knowing where to find free stuff and what to watch out for.

From free samples to swap parties to Freecycle.org, opportunities abound. Free can truly be a four-letter word in retail, but it's often an alluring one to both givers and takers. It can successfully launch a product — or artist, as free music downloads have proved — but can also cut deeply into companies' profits if it becomes the norm. And consumers, of course, need to monitor how much they're spending (especially on stuff they truly don't need) to get the freebie.

Chris Anderson, editor-in-chief of Wired magazine, calls the trend "freeconomics."

"Once a marketing gimmick, free has emerged as a full-fledged economy," says Anderson, whose book Free! Why $0.00 Is the Future of Business, comes out next spring. "The psychology of 'free' is powerful indeed, as any marketer will tell you."

No industries give away more free stuff to drive sales than those selling cosmetics and other personal-care products. Estée Lauder and other companies regularly offer free gifts with certain minimum purchases.

And stores will sometimes throw in free gifts of their own, as Neiman Marcus does for purchases of $100 or more during its twice-yearly "Beauty Event" (which starts today, offering free "crocodile-embossed tote in cranberry with nine treats"). Anderson notes that King Gillette helped launch the razor business in the early 1900s by selling bulk razors to companies to give away for free, although recipients still had to buy the blades.

Mike Essex, author of the book Blagman: Don't Buy It, Blag It!, has filled an apartment with stuff he's gotten for free by offering to review the products, which he does on his "Blagman" blog. He recommends the tactic, which he honed while reviewing video games for a living, to anyone looking for free stuff.