Online travel agency (OTA) stocks have had their struggles lately, but few have struggled more than TripAdvisor (TRIP 0.66%). On the back of disappointing third-quarter results, the lack of movement in its core business, and a rise in marketing costs across the industry, TripAdvisor's stock has been hammered over the past year.

This is in sharp contrast to the two 800-pound gorillas that dominate the OTA patch, Expedia (EXPE 0.32%) and Priceline Group (BKNG 1.13%), both of which have risen despite the industry's challenges. The depressed price of TripAdvisor does present a juicy opportunity for investors, though. Here's why.

Tourists reading a map in front of London's Tower Bridge

Image source: Getty Images.

Attracted to growth

In 2014, TripAdvisor decided to pivot its business. That's not an unusual move for a young-ish internet company, nor was it a bad idea. The site had (and still has) a mass viewership of people who utilize it for its many consumer reviews of travel offerings. That year the company introduced an instant booking feature, allowing those impressed enough by a review to book a stay in the property.

Sensible doesn't necessarily mean successful, though. In spite of a sustained and concentrated ad campaign aimed at making travelers aware of the feature, TripAdvisor's revenue from hotel bookings hasn't grown to any impressive degree. 

At times, it hasn't grown at all. In the company's third quarter of 2017, the take from hotels (and other forms of lodging) actually slumped by 3% on a year-over-year basis, dropping to $312 million. As this category comprises far and away the bulk of revenue, it's hardly a surprise that the market has punished the stock lately, driving shares from around $50 at the beginning of 2017 to $35 today. 

But lodgings aren't the only way TripAdvisor makes money. The company's nonhotel revenue has been climbing sharply and has taken an increasing share of the overall top line. As sluggishly as TripAdvisor has performed in the hotels segment, it's done gangbusters with nonhotel.

This is due in no small measure to its attractions, a big collection of travel experiences it advertises on its site. They helped power nonhotel revenue, which in said quarter increased by 26% to $127 million. The latter was nearly 30% of total revenue, up notably from the year-ago figure of 24%.

Happily, TripAdvisor management intends to devote resources to building the attractions business (although it's a bit short on specifics). That's promising because even though growth in nonhotel take has actually slowed a bit, it's still quite impressive at those double-digit rates. And the runway is long -- even if nonhotel doesn't reach the company's rosy predictions of $1 billion annual revenue, there's still plenty of business to be had.

Another plus for TripAdvisor is that over the past four years it has managed to increase its traffic numbers nicely, to an average monthly unique visitors count of 455 million in Q3. That's a sturdy 17% improvement over the year-ago quarter, and more than double the tally of early 2014.

A nice niche

So what we have here is a site that continues to bring in more travel aficionados, who are obviously willing to spend money on more than just a flight and a hotel. TripAdvisor is struggling to compete in a crowded field in hotel bookings; it's hard to win against the powerful one-two punch of Expedia and Priceline, not to mention the hundreds of other booking sites at a web surfer's fingertips.

What it can do is carve out a solid niche for itself in the attractions segment. So far, it seems as if that's working; this opportunistic company has identified a good source of growth and is obviously willing to exploit it. Its management is sensible and focused, so I'd give it a good chance to do so in an effective way. If it manages this feat, its stock could start climbing steeply like Priceline and Expedia have lately.