And that's where the real potential of iRobot lies. Buck says that after years of researchers working independently on a variety of robot technologies -- sensors, imaging, manipulation, reasoning algorithms -- the field of robotics is starting to become interdisciplinary enough to make basic but useful robots for mass production. "We're only starting to get to the point where all these technologies are being put together in such a way that they can be used in the consumer market," Buck says. Such robots are likely to first address other basic chores such as fetching objects or washing windows. iRobot's prospectus cites some research on its market's potential size: The United Nations Economic Commission for Europe estimates $2.6 billion in worldwide spending on household robots between 2004 and 2008. And the Japan Robotics Association projected the global market for home robots to reach $12.3 billion in 2010. At Thursday's closing price of $34.50, iRobot's stock is trading at 265 times its trailing 12-month profit. But in the third quarter, the company managed to boost revenue while keeping costs under control: R&D costs were 5% of revenue, compared with 10% in the second quarter and 18% in the first. SG&A costs were 15% of revenue, compared with 26% and 31% in the two previous quarters, respectively. If that trend keeps up, the stock will approach a more earthly valuation. If iRobot's shares are going to become as popular as its Roomba has proven to be, it will have to act like the Roomba itself: It must suck up investor capital without bumping into any walls. So far, it's off to a good start.