There is no shortage of places to sell your stuff online — the Internet has often been referred to as a "global swap meet" over the years. Of course, with the anonymity of operating online, a great amount of caution (and some healthy skepticism) is always recommended. Using an established third-party Web site as a broker between buyer and seller is one of the best ways to protect yourself.
Perhaps the best-known way for individuals to buy and sell things online is eBay, which can be used for anything from clothes and toys, to cars and rare collectibles. The payment system used for eBay purchases, called PayPal (also owned by eBay), offers fairly robust fraud protection, and overall, eBay has put a lot into conflict resolution — although they generally tend to favor the buyer.
Another, less-well-known site owned by eBay is Half.com, where you can sell books, movies, video games and other media. Instead of an auction system, these are fixed price sales, where you list your item and how much you're selling it for. You may not get as much for your stuff on Half.com, but the advantage is that eBay handles all the billing and just deposits the money in your bank account.
Amazon also lets individual buyers sell items, and your copy of a book, video game, or DVD will be listed on the same product page as new copies of that item. Again Amazon handles the billing and you have to give Amazon your checking account info to get paid. Both Amazon and eBay charge a small commission on sales, and eBay also charges a small insertion fee to list an item. Amazon also makes it fairly easy for musicians, for example, to sell their albums through the Amazon store, as both CDs and MP3s.
Etsy.com is another eBay-like marketplace where people buy and sell a lot of craft and jewelry items. Unlike eBay, they just act as a facilitator, connecting buyers and sellers, after which it's up to you to make payment and shipping arrangements — which are often done through PayPal, the payment service owned by eBay.
Craigslist is the most open-ended of all these systems — it's essentially just a big online bulletin board where you can list just about any item. The Craigslist organization offers no warranty that either buyers or sellers are representing themselves honestly, and it's completely up to you to make arrangements to pay for and pick up a purchase.
Because of its local nature, most Craigslist transactions end up taking place in person. In those cases, you want to exercise a great deal of caution, whether you're the buyer or seller. I've bought and sold everything from furniture to concert tickets to musical equipment through Craigslist, and have been fortunate to never run into a problem. But when meeting a stranger to hand over an item, you should make sure it's in a safe place, and that both parties examine what they're getting carefully. A buyer doesn't want to end up with a brick in a box, and a seller doesn't want to end up with an envelope full of Monopoly money.
Something to beware of, especially on Craigslist, but this goes for any online sales, is any kind of suspicious requests regarding funds. PayPal or, for Craigslist, cash, are the safest ways to go. Anyone asking to pay with a cashier's check, some kind of wire transfer, or anything unusual like that should be a big red flag. One common scam (that hopefully most people know about by now) involves a buyer concoting a convoluted excuse to send a cashier's check for more than the sale amount, and asking you to send the item and the difference back to them. Of course, the check ends up being phony, even if it initially clears your bank, so you're out the sale price of the item, and the money you returned to to the seller.