I recently bumped into Tim Jackson and after talking about films, he invited me to join his nascent online DVD swapping social network LendAround.
A DVD swapping service? Ah, well, those are harder to pull off than it might seem. The other attempts I’ve seen fail due to a mismatch of movie quality and gradual attrition.
Tim’s response, which he’s generously let me republish here:

This is the first time anyone’s really thought through how a lending system can actually work, and built it.
Three reasons why it’s different, three why it’s better.
DIFFERENT
1. It’s lending, not swapping or trading: that means it’s about sharing stuff you like, not dumping stuff you hate. You get things back afterwards. Our early user research discovered that if you ask people to list things they want to swap, they basically just reveal 10% of their collection (ie the stuff they hate). Ask them what they’re willing to lend, and they reveal 90%.
2. It’s about friends, not strangers. Our research revealed that people need help getting used to borrowing and lending. Asking everyone to open their collections to the world right from the start doesn’t work. We have built in little messages so you can say something directly to your friend when you lend to them or borrow from them. You can of course add (and silently remove) friends dynamically and individually; there have been previous systems of closed groups (eg students at x university) but these missed the point that you may not trust someone you’ve never met just because they study at the same college as you do.
Note: if you’re thinking that sounds like Facebook, yup: we’ve also built a Facebook app, so you can invite FB friends and they can see your collection and learn about what you’re watching and borrowing.
3. We’ve built technology to support pass-ons. This one is subtle and you only discover it after using the system a bit, but it’s incredibly important. Suppose I lend Fight Club to my friend Michael . You’re also my friend, but you don’t know Michael at all. What happens when you ask to borrow the movie while Michael has it? In previous lending systems, he’d send it back to me, and I’d send it on to you. But we’ve set things up so that if you want it, Michael can send the movie onwards to you without even knowing you.
Here’s how it works: you get an email saying please pass on the DVD. When you click on it, you download a printable letter-sized sheet that folds into a wrapper showing Michael’s address. You simply put the DVD inside (in a clamshell or sleeve — we’re sending them out free to beta users later this month), and put a 43c stamp on it. (Or if you’re a student on campus, a wage slave in a big office, or a resident of a big apartment building, you walk it round for free.)
Here’s why this is a really big deal: fast-forward to when you have 50 friends who’ve each lent out five movies. Without pass-ons, once things start working, you’re soon going to start feeling that you have an unpaid job dealing with returns and requests. With pass-ons, your 5 DVDs can circulate among your friends without you knowing or caring who has it (remember that you can always instantly excommunicate anyone, find where each of your DVDs is, and request an immediate return, and that your friends can’t pass on your DVD to their friends). And from your perspective, the service begins to look like Netflix for free — you receive a disk, print a wrapper, and pass it on. The only work you have to do is in connection with new movies that you’re enjoying watching.
Also, think of the speed and environmental benefit. With rental-by-mail, each movie makes two journeys per viewing: out and then back to the warehouse. With us, it makes one journey — twice as fast, half the environmental impact. Instead of going in to the center and out, our users’ DVDs go round — that’s why we called it LendAround.
This will raise lots of questions in your mind (eg I don’t have stamps, when will you start to print the postage on the wrapper?), and I’m happy to answer them. But we’ve taken a strategic decision that you only have 30 seconds to explain to potential users what you’re doing, and so it doesn’t make sense to shout about this now. What we’ll do instead is gradually introduce people to the functionality we’ve built as they become first members and then active members.
BETTER
1. No credits, bucks or fake currency, and no fees. Other services worked by giving you credits for each item sent; some added a charge to you when you receive something, eg a ‘mere’ 79 cents fee for each swap. We think quasi- or real currencies reduce usage and promote abuse and attempts to game the system. Our focus is about encouraging people to be sociable and friendly.
2. No need for simultaneity. Some attempts at swapping have relied on bilaterality (ie you want to find someone who’s got Fight Club and wants The Ten Commandments), or have created complex multilaterality, where they build a chain of people who can each pass an item around so that everyone gets their request. Such complexity reduces the probability of successful matches, and hence the number of ‘transactions’.
3. Network, not personal requests. Once you invite some friends, you’ll probably find I’m not the only person you know who has Fight Club. In other systems, requests are made directly from one user to another. What we do is different. When you request Fight Club, we can check to see who’s got it, and make an intelligent decision about where to request it based on not only availability but also other factors like the reliability of the other person and outstanding balances of borrows and lends. The result is that while you make only one request, we can work in the background to find the smartest way to fulfil it. And if someone you know only buys Fight Club after you requested it, then your loan request can still go to them.
I know it’s hard to convey the subtleties of all this in a 500-word post. But we’re convinced that once a user signs up, there’s a much higher probability of our being able to give them a reliable and useful service that they love.

The jury’s still out, but have a quick peek at LendAround and tell me what you think.