iRobot Corp

Despite the crowded competitive landscape, we expect strong domestic growth to continue for this narrow-moat firm, with only 10% of households owning a vacuum robot.

In an excerpt from their new book, Morningstar's Heather Brilliant and Elizabeth Collins explore how to identify a moat and how intangible assets can help a firm carve out a sustainable competitive advantage.

Earnings disappointments so far have largely been tied to overseas--not U.S.--weakness, as well as sector-specific issues, says Morningstar's Bob Johnson.