2. Online auctions

If you're willing to compete with strangers around the world, you can snag an infinite number of deals on auction sites. Ebay.com is the best known, but there's also Ubid.com and Ebid.net.

How it works: Sign up for a free membership. Browse for the item you're looking for. Once you find it, check the opening bid and how much time you have to make an offer. Before you enter a bid, click on the item to read more about it. Auction sites often let buyers post feedback on sellers. Read it. Also read the sales policies of the auction site.

If you're satisfied with your research, enter a reasonable bid. If your bid is the highest when the clock runs out, you win! On eBay, you sometimes have the option to skip the auction and buy the item outright for a set fee.

It's important to note that once you've won an auction, you're financially obligated to go through with the transaction. So make sure you're sure. Should you have any issues with the product or seller, eBay offers a buyer protection plan that covers many items purchased on its site. In some cases, the company will cover your original price and shipping costs. It will contact the seller on your behalf.

Safety tips

• The seller will advise you how payment will be accepted. Back out unless you can use a credit card or a PayPal account - they offer some protection against fraud. Using a debit card linked to your main checking account is not a safe idea: Once money flows out, you'll have a hard time getting it back if there's trouble.

• It's worth repeating that you should take the seller feedback seriously. Make sure your seller has a high rating before you deal.

• Beware of fraudulent emails that may come to you after you've made your purchase, particularly if they have links for you to click on.

3. Online marketplaces

Shoppers flock to websites such as Amazon.com and Half.com because they're one-stop shops where you can buy virtually anything, from music to power tools. Companies compete along with individual sellers for your attention.

How it works: Browse for the jazz album or sander that you want. When you've found it, check out which seller is offering the best price. Do you want to buy used or new? The option is yours.

Safety tips

• Look at the sellers' ratings if they're available. Is the feedback positive?

• As with auctions, the seller will advise you on how payment will be accepted. Go through with a deal only if you can use a credit card or a PayPal account.

• Use a secure checkout process. How do you know it's secure? Look for the "s" at the end of "http" on your browser address when you get to the transaction page.

• Also, look for a closed padlock icon. Click on it and it will show you security details. If the lock is open, you should assume the site is not secure, Lombana says. "Some fraudulent sites are built with a bar at the bottom of the Web page to imitate the lock icon."

• Read the return and refund policy on the site so you know your rights as a consumer.

Stacy Julien is a writer and editor at AARP Media.

Remember to go to the AARP home page every day for tips on keeping healthy and sharp, and great deals.

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