It's been a wild ride for iRobot (NASDAQ: IRBT) shareholders so far in 2018. A month ago, the robotic pioneer's shares fell 30% after it reported fourth-quarter 2017 earnings.

The market apparently got all worked up over several short-term concerns. One was the company's earnings miss, which largely was the result of a one-time tax charge it booked because it was taking advantage of the recent U.S. corporate tax cuts to repatriate overseas profits. Analysts were also disappointed with management's guidance for fiscal 2018 EPS in the $2.10 to $2.35 range, which was short of consensus expectations.

Don't let these near-term issues fool you (with a lower-case "f"): iRobot is establishing itself as the leader in the important consumer market for robots. Long-term investors would be wise to hold onto their shares, regardless of last month's volatility. 

Moreover, here are three reasons why I believe iRobot is still an excellent buy-and-hold stock.

A picture of a hand drawing an arrow going up and to the right.

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Core growth here at home

iRobot noted that its Q4 consumer revenue grew 47% in the United States -- its largest and most profitable market. Its flagship Roomba robotic vacuum now is featured in endcap displays at retailers like Lowe's and Home Depot. And that strong growth rate suggests that it sold well during the holiday quarter.

The company's newer Braava mop also made a nice contribution to the top line with 65% sales growth. iRobot began advertising the Braava on television last year, and its commercials certainly seem to have paid off. The Braava just celebrated its second birthday as a product, and it already accounts for 9% of overall sales. 

We'll be watching for new ideas to come soon. CEO and co-founder Colin Angle has already hinted that several products will launch in the second half of this year. The company's core technology is translatable to a wide variety of uses.

Key point: iRobot's growth within its most important market is still strong. 

Others nations; now with cleaner floors

Even though iRobot's advertising attention may be focused on the U.S., its products are receiving a warm welcome abroad.

International sales increased 28% during 2017, driven by growth in Europe and Japan, both markets where the company recently transitioned to selling directly to consumers rather than through distributors. This strategy provides higher margins (no longer having to pay the middleman), but the question of whether it's truly effective will be answered by their sales growth rates.

With European sales up 46% in 2017, and Japan's up 28%, the plan seems to be working nicely. 

One market that remains a challenge is China. Lower-priced knock-offs still thrive there, and iRobot's sales fell 27% year over year in the country. Management acknowledges that the competitive dynamic isn't likely to change any time soon, and that China isn't the best match for iRobot's premium-priced products. Accounting for less than 5% of total sales, the world's most populous country isn't expected to be a huge contributor to future revenue.

Key point: iRobot's brand is successfully translating overseas in most markets.

The technical edge

Lastly, I think it's important to recognize the street cred that iRobot has earned after doing business in robotics for nearly 30 years. Originally a provider of bomb-detecting robots to the Defense Department, it has always been an innovator in the field. They were quick to equip their robots with cloud connectivity for software updates. And it recently incorporated functionality that allows its devices to work with Amazon's Alexa for the smart home. 

Media headlines and recent short reports suggest that iRobot's premium prices and robust margins will be unsustainable as more competitors enter the market. I would argue the opposite -- that iRobot is the innovator others are copying, but it remains a step ahead in developing cutting-edge products and technology.

I liken iRobot's offerings to Apple's Smartphones or NVIDIA's graphics processing units -- both still command a premium due to their supportive ecosystem, even though there are lower-priced options available. I don't personally see much threat in competitor SharkNinja taking a technological lead any time soon.

Key point: iRobot's established technological ecosystem puts it ahead of new competitors.

The Foolish bottom line

Don't sweat the small stuff. As Foolish investors, we prioritize long-term drivers over short-term concerns. iRobot's market leadership domestically is translating abroad, and its technology remains several steps ahead of that of its competitors. That one-time tax charge and its light guidance were merely speed bumps in this company's long road to success.

Simon Erickson owns shares of iRobot. The Motley Fool owns shares of and recommends iRobot. The Motley Fool has a disclosure policy.