Penny-pinching bibliophiles will revel in a new batch of Web sites for paperback swapping. The sites reinvent the classic act of trading summer beach reads and expand summer reading beyond the dusty bookshelves of friends and family.

We tested four Web sites devoted to exchanging books -- Paperbackswap.com, Swaptree.com, Bookmooch.com and Bookins.com.
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Wesley Bedrosian

Unlike Amazon.com, users don't have to pay for the actual book, just shipping. Unlike with a library book, there's no due date (or late fee). These sites allow readers to browse the collections of site members across the country and unload books that they no longer want in their permanent collections.

Paperbackswap.com says it is the oldest and biggest swapping site. Over 35,000 trades take place a week,according to Richard Pickering, the site's founder.

The way it works is you post all the books you're willing to swap with other site members. You get two free credits for posting your first 10 book titles. (One credit is redeemable for one book.) You earn an additional credit for each of your books requested by (and sent) to another member. We posted books ranging from well-circulated titles like Tom Wolfe's "The Bonfire of the Vanities" to classics like John Steinbeck's "The Pearl." If you don't want to post books, you can buy credits for $3.45 a credit. Within a few hours, we had requests for three of our books.

You can search for books you want by title or browse by genre. You can also upload books you want from your Amazon wish list -- and receive an email notification when the books become available. We were on the hunt for a copy of "Catch-22."

When someone requests one of your books, Paperbackswap creates a mailing label (preprinted with the intended recipient's address) for you that you print out on standard printer paper, designed to wrap around the book. The paper wasn't big enough for some of our larger books, creating a scramble for envelopes. You can pay for postage via the site or choose to put it on yourself. Also printed on the label are estimates of what the media rate postage would be. Two of our three labels got the price right ($2.23) but the third was 20 cents too low. Media mail, the cheapest rate, can take 14-21 days, so patience -- both on the giving and the receiving end -- is important. Our copy of "Catch-22" took over two weeks to arrive after our request. We never did snare a copy of Michael Pollan's "The Omnivore's Dilemma." It sat on our wish list for weeks without a match.

Paperbackswap functions a bit like a book club, with heavy participation from users. You can "friend" other swappers and even make requests when sending books, like asking if the book comes from a nonsmoking member. The sender of "Catch-22" not only sent us a message that he shipped the book, but an additional comment about how he loved it and hoped we did, too.

Swaptree.com allows users to trade books for DVDs, CDs and movies. Access to the selection of books (around 700,000 total) is based on what you've got in your multimedia arsenal. Unlike Paperbackswap.com -- where you exchange books for credits -- with Swaptree.com, you do a one-to-one swap with another user. So, if your items are in high demand, the number of things you can swap for increases.

For example, when we tried, our copy of Augusten Burrough's "Running With Scissors" could be swapped only for any one of 140 different books, two different CDs, 12 different DVDs or five videogames because all of the owners of those things had "Running With Scissors" on their wish lists. Browsing these options was easy, thanks to a crisp layout of book covers and short summaries of the books when you hover your cursor over the book. You can also easily import your wish list from Amazon to your Swaptree "books i want" list.

The selection here was decent. Still, none of the books being offered for "Running With Scissors" caught our eyes. And the owners of books we wanted all had very specific titles they were willing to swap for (which we didn't have). So none of the 10 books we wanted were available for us to swap.

You have to upload books you want to swap by ISBN (an identification number assigned to books), but we found that to be a bit of a pain since some of our older paperbacks didn't have them and we had to search Amazon to find the numbers. Swaptree also offers the option of printing out a mailing label and can charge your credit card for postage. Most books cost around $2 apiece to send. Users are also encouraged to interact with each other and submit reviews.

Bookmooch.com follows a similar model but has a smaller selection of titles (500,000 books) and a less graphically pleasing setup. The site basically consists of lists of text links and a simple search function. And sometimes books were misshelved. (We encountered an illustrated copy of "Lord Jim" in the comics and graphic novels section.) Although every book on Bookmooch.com has a link to the Amazon page, the book reviews on Bookmooch weren't that in-depth. But Bookmooch has an international edge -- the site is available in seven languages.

You earn 1/10th of a point by adding books that you want to give away, one point for sending it away, three points for sending it to another country and 1/10th of a point for acknowledging receipt of a book and offering feedback. You can receive a book for one point, or two points if it is coming from another country. You can't buy points, but you can contribute some of your points to Bookmooch-selected charities.

No one requested any of the 10 titles we posted. We also didn't find many titles we wanted. For shipping in the U.S., the cost is also media rate, around $2 a book. Moochers have to create their own address labels and estimate postage via a link to the USPS shipping estimator.

At Bookins.com, books are assigned point values calculated by factors including popularity, age, awards won, and how old the book is. You get 15 free points when you sign up. Users also pay to receive books rather than send them. The shipping cost, however, for one paperback was $4.49, nearly twice what we paid for Paperbackswap.com shipping. Yet the Bookins title we requested ("Middlesex" by Jeffrey Eugenides) arrived only a week later. (Since it was a popular title, we had to pay eight points for the book.) Mitchell Silverman, the site's founder, said that the higher shipping price includes bar-code tracking: The site automatically tracks the packages and reports when they arrive.

The approximately 500,000-book selection here wasn't as diverse as that offered by other sites. Hard-core literature lovers shouldn't be shocked if they find a Harlequin romance novel alongside Shakespeare. However the site had nifty lists of books available that were Oprah's Book Club selections or Pulitzer or Hugo Award winners, among others. You can also browse by books most wanted by users, most available and most traded.

To get the most out of these sites, it helps to have some flexibility when it comes to what you want to read and several weeks to spend browsing online and waiting for shipping. It might be perfect for lazy reading, but definitely not the best bet for snagging a hot title on short notice.
WEB SITE/SERVICE SETUP EXPERIENCE COST COMMENT
Paperbackswap.com You get two free credits for listing your first 10 books and 1 credit for every book you send away. You pay to mail your books, earn a credit, then go and pick a book you want. Each book costs 1 credit. Fellow members seemed highly engaged in the trading and felt more like a book club than just an exchange. One of the printed postage labels was 20 cents off and the wrappers didn't fit. $2-$3 for shipping. You can print postage from the site or buy it on your own. By far the largest selection of books to choose from and greatest response to the books we posted. We liked being able to exchange messages with other readers.
Swaptree.com You post an item and see who is looking for it. You look through the other user's collection of books, DVDs, CDs and videogames, then swap for one of the other user's items that you want. It's a one-for-one trade. The site itself was extremely usable, but the selection is limited by what you're posting. System is much better for really popular titles rather than more obscure or older books. $2-$3 for shipping. You can print postage from the site or buy it on your own. Uploading items that we had by ISBN number was difficult, but uploading our wish list from Amazon.com saved a lot of time. The book's pages had links to Amazon, so we could easily buy if the title wasn't available via swapping.
Bookmooch.com It costs one point per book, or 2 points if from another country. You earn 1/10th of a point by adding books to swap, 1 point for sending, 3 points for sending to another country, and 1/10th of a point for acknowledging receipt of a book. At first, the point system was confusing and the site was difficult to browse, however the international aspect was intriguing. Varies depending whether users opt to trade only within the U.S. or with other participating countries. Option to donate money to charity is neat. Site is available in seven different languages -- English, German, Spanish, French, Italian, Portuguese and Japanese.
Bookins.com Swapping is based on a point system. Books are assigned values based on 50 to 60 different factors. You get 15 free points when you sign up. Unlike with the rest of the sites, users pay to receive books rather than send them. The shipping cost for one paperback was flat-rate $4.49 and includes delivery confirmation. $2-$5 The lists for browsing were helpful, but sometimes titles were miscategorized. Book arrived quickly. By giving points to books, users have an incentive to post diverse, fresh titles rather than traditional beach reads.

Write to Mary Pilon at mary.pilon@wsj.com