Yesterday after the market close, shares of iRobot Corporation (IRBT 7.09%) plunged more than 5% after the company turned in better-than-expected fourth-quarter results.

iRobot reported Q4 sales of $126.3 million, which translated to net income of $0.11 per share. By contrast, analysts were looking for earnings of just $0.10 per share on revenue of $125.5 million. So why the drop?

In short, the market initially chose to focus instead on iRobot's light 2014 earnings guidance, which calls for net income per share between $1 and $1.15. By comparison, the midpoint of that range stood well below Wall Street's expectations for earnings of $1.14 per share.

However, after opening down around 4% this morning, iRobot stock has gradually clawed its way up to an impressive 12% gain as of this writing. So what changed?

Guidance could be conservative
First, consider the evolution of iRobot's full-year earnings guidance last year. 

Last February, for example, iRobot called for 2013 earnings per share of $0.57 to $0.72. Then in April, iRobot raised its full-year guidance to a range of $0.80 to $1 per share. Then in October, the company narrowed its expectations to a range of $0.90 to $0.95 per share.

When all was said and done, iRobot's 2013 earnings came in at $0.94 per share, or the high end of its already-raised, narrowed guidance.

Long story short: It's difficult to accurately gauge full-year earnings, and investors are taking solace knowing iRobot has made a consistent habit of underpromising and overdelivering.

Home robots are just getting started
Next, if we're to believe comments from management during the subsequent conference call, things are going swimmingly for the robotics specialist in the home.

Home Robots are expected to lead the way again this year, with sales expected to grow 17% to 20% and comprise around 90% of total company revenue -- a great thing considering iRobot's Defense & Security business is anticipated to remain depressed and perform at 2013 levels.

Relatedly, CEO Colin Angle elaborated that sales of iRobot's revolutionary new Roomba 880 "have exceeded those of all other new products over the same timeframe." That's no small feat considering the Roomba 880 is currently exclusive to iRobot's website and selling at a steep $700 each.

iRobot's new Roomba 880. Image source: iRobot.

Better yet, Angle provided some compelling long-term perspective with the following statements:

The robotic vacuum cleaner market grew roughly 30% from 2010 through 2012 and represents approximately 15% of vacuum cleaner sales. That revenue share is comparable to the level of other disruptive household appliances, such as the microwave oven and dishwasher, at the same stage of their life cycles, 10 to 15 years following introduction. We believe that as awareness of the category continues to expand, we could see an adoption rate similar to those other appliances.

Meanwhile, the jury's still out on the new Scooba 450, which was introduced at CES this year and is the first major new large-format floor Scooba floor-washing bot in almost eight years. Still, Angle insists they believe it will enjoy "a large addressable market, both domestically and overseas."

Telepresence is still in its infancy
Finally, iRobot didn't provide much in the way of updates for its Ava 500 video collaboration bot, only saying it remains in beta "with several global 2000 companies from various industries." However, it did sell around $1 million in product last quarter related to its RP-VITA telepresence robots, which only began to gain traction in the health care industry last May.

As it stands, while investors shouldn't expect iRobot's Remote Presence business to make any material contributions to growth this year, it remains a potential bright spot down the road.

Foolish takeaway
I'll admit shares of iRobot look expensive trading around 40 times last year's earnings. But that's of little consequence if iRobot's most significant growth still lies years down the road. In the end, the market's a forward-looking machine, and at this point iRobot's very long-term potential has never looked better.