What happened

Shares of iRobot (IRBT -1.80%) were down 12.1% as of 2:30 p.m. EDT Wednesday after the home-robotics specialist announced third-quarter 2019 results and revised its full-year guidance.

That's not to say iRobot's quarter looked bad at first glance. Revenue climbed 9.4% year over year to $289.4 million, translating to adjusted earnings of $43 million, or $1.50 per share. For perspective, Wall Street's consensus predictions called for earnings of $0.52 per share on revenue of $259.4 million.

iRobot Roomba S9 and Braava m6 robots docked near a wall in a home.

A Roomba S9 robotic vacuum (left) and Braava m6 robotic mop from iRobot. Image source: iRobot.

So what

So why the drop? For one, according to CEO Colin Angle, iRobot's growth was partly bolstered by "a large shipment to a major U.S. retailer that was previously planned for the fourth quarter."

In addition, Angle said sell-through during the quarter was "suboptimal" following the company's decision to raise prices in July to offset the impact of recently increased tariffs. As such, he said, given its "belief that the [robotic vacuum cleaner] category was at a growth inflection point prior to tariffs," iRobot decided to revert to pre-tariff pricing on most products in an effort to drive top-line growth and maintain market share.

Still, U.S. sales during the quarter fell 7% year over year (to $117.9 million), partly offsetting the company's much stronger 25% international growth (to $171.5 million).

Now what

For the full-year 2019, iRobot revised its guidance for revenue to be in the range of $1.20 billion to $1.21 billion (compared with $1.20 billion to $1.25 billion previously), which should translate to 2019 earnings per share of $2.60 to $2.80 (narrowed from $2.40 to $3.15 before).

In the end, the market obviously doesn't approve of iRobot's strategy of forsaking profits in favor of driving revenue growth in these early stages of the home-robotics market. And the stock is responding in kind.