Billmonk, track money owed between friends

Billmonk is a web service that helps users organise their "social money", defined by the site as the informal currency between friends. So for example, you're out for dinner with a group of friends and the final bill has to be split in some way. Who owes who what? And to complicate things further, different people are likely to 'settle up' at different times. Things aren't always written down and the process can sometimes put a stress on friendships. Billmonk hopes to solve this problem by managing social money "in a manner that is easy and fair." Once signed-up, you tell Billmonk any email addresses that are associated with your identity (as that's the means by which other friends will find you), and fill in a short optional profile. You can also add your cell phone number to your account in order to use Billmonk via SMS. The home page presents you with a very simple interface: on the top left is an overall balance telling what you're owed and what you need to pay out. In the centre are options to create a new loan or debt, new shared bill, new itemized bill, report payment, and settle up (using the company's Obopay system). You can also populate your account with friends ready for future social money dealings.

As an example I decided to add a 'shared bill'. The first screen asked me for details such as the total amount, date, and to describe the occasion. The second screen then asks who actually paid, and who participated. From there it calculates who owes whom what, with the option to make adjustments if somebody skipped a course or didn't drink for example. Anybody associated with this shared bill will see what they owe when they log-in to their own Billmonk account.

As mentioned earlier, Billmonk also has mobile SMS functionality so that you can send a simple text message to register a new social expense. For example, sending "55 3 sushi dinner" means "I paid £55 for a sushi dinner for 3 people." Then next time you're online you can fill in the details. Billmonk is an interesting service that the company says is particularly popular with roommates, young professionals, and college students. The broader phenomenon of "social money" is also an intriguing concept, and I was interested in how Billmonk was conceived. I caught up with Gaurav Oberoi (via email), who along with Chuck Groom founded Billmonk, to find out more. How did you come up with the idea? What problem does Billmonk solve?
The idea for BillMonk came from a trip to Europe with a group of friends. We knew that there would be lots of large expenses like train tickets, museum passes, hotels, and fancy meals, and we didn't want to worry about who would pick up the next tab, or about being unfair. We also didn't want to have to carry wads of cash around. So to make our lives easier, we rotated who paid for the next group expense, and wrote it down in a special notebook. When we returned, I entered the bills into a complicated spreadsheet which did the necessary math and computed who owed who what. We emailed the spreadsheet back and forth a few times, then wrote each other checks, and we were done! It was only a short step away from here to thinking about how useful a centralized bill tracking system would be. A couple of years after the trip, Chuck and I finally set out to build BillMonk with the aim of making money management between friends painless. Tell us a little about the company, who founded it / funding / who owns it now?
The company was founded by Chuck Groom, and Gaurav Oberoi, two ex-Amazon engineers, in the fall of 2005. It was self-funded, and was run out of our apartments in Seattle, WA until the end of 2006, when it was acquired by Obopay Inc, the first comprehensive mobile payments service in the US. Obopay allows users to get, send, and spend money instantly from their mobile phones, anytime, anywhere. It's a perfect match for BillMonk, because you can see how much you owe someone, and immediately settle up via Obopay. Obopay also offers users a free MasterCard prepaid debit card that is linked to their Obopay account, and can be used at any ATM or merchant that accepts credit cards. The end result is that friends can track bills, settle up instantly, and have immediate access to their cash - and all of it can be done on the go from their cell phones. How many users do you have?
While we're not disclosing numbers yet, we have been growing steadily since launching in January 2006. What's the revenue model? BillMonk drives Obopay transactions. When users settle up using Obopay, they will be charged a transaction fee. It's free to use, right?
BillMonk is completely free. If you wish to settle up debts using Obopay, you will be charged a nominal fee of 10 cents each time you send money. Thanks Gaurav for taking the time out to answer my questions.