Source: Marriott.

Marriott International (MAR -0.13%) is expanding all over the globe, and its share price is expanding as well, up over 50% in the past 12 months. Following an impressive Q2 earnings release with 25% higher earnings over the same quarter last year, and more impressive results than competitors such as Hilton Worldwide (HLT -2.19%) and Starwood Hotels (NYSE: HOT), is this company still one investors should try to get in on, even after its recent run? Let's look at a few reasons this stock could still be poised for more long-term growth.

Marriott's Q2 is likely to set the stage for more wins
Marriott's impressive 25% year-over-year earnings increase in Q2 came not only from a growing number of properties, but also from more gained at each property. The company was able to raise its
RevPAR, or revenue per available room, with Q2 global RevPAR growth of nearly 6% year over year.

In its Q2 earnings release, Marriott management raised RevPAR guidance for the rest of the year, and analysts expect that RevPAR will continue to increase this year and next, especially in the company's higher-growth regions such as Latin America, where it could see double-digit RevPAR growth by year's end. Higher RevPAR combined with a growing number of properties will mean even more impressive numbers in the coming quarters, as Marriott continues to make more rooms available and get more revenue from each room.

It has the best margins in the industry
One reason Marriott is a RevPAR winner is that it has the best margins in the industry, both by gross margin (percentage of revenue retained after direct costs are accounted for) and operating margin (income as a percentage of net sales).

 MetricMarriottHiltonStarwood
Q2 Revenue Growth YOY 6% 4% (1.5%)
Gross Margin 0.69 0.40 0.47
Operating Margin 0.42 0.18 0.26

Sources: Selected companies' earnings reports, Yahoo! Finance.

The company is doing a great job of controlling direct costs associated with sales, while operating efficiently to drive more of those sales all the way to the company's bottom line. As more revenue comes in from higher RevPAR, these margins mean that income will probably increase even faster for Marriott than for competitors Hilton and Starwood. 

Marriott is investing in future growth worldwide
Marriott has been aggressively expanding its brands around the world. In the most recent quarter, the company added 162 properties, including 18,729 rooms. Marriott's total portfolio is up to 4,087 properties globally, with nearly 697,000 rooms total. Now the company is making its portfolio even larger by adding more properties in key markets around the world.

Marriott still counts on its North American market for much of its sales, with around 50% of its locations there. However, the company has chosen key international markets to focus growth on in the future, including China, Latin America, and Africa.

While growth in China may be slowing slightly, Marriott still sees the country as a high-revenue market and continues to expand there. Likewise, Latin America has already been a lucrative region for the company, and it will be especially so in the next few years, as Marriott currently has 35 projects underway in the region. With increasing RevPAR rates in Latin America, properties there should be even more profitable going forward.

A room at one of Marriott's newly acquired Protea hotels in Africa. Photo: Marriott.

But it's Africa that makes up the most exciting development push for the company right now. In April, Marriott acquired African hotel group Protea, which included 117 properties in seven African countries, making Marriott the largest hotel brand on the continent. Marriott plans to expand that number further with an additional 40 properties in up to 13 African nations by 2020.

Is Marriott the best buy now?
Marriott isn't the only company seeking growth around the world, and both Hilton and Starwood are also seeking expansion in China, Latin America, and even Africa. So for investors who are looking at the hotel industry now, which company looks like the best value and shows the most potential for more future growth?

Marriott is selling at a slight premium to the industry average, at a P/E of 29 -- above that of Starwood at just 25 but well below that of Hilton at around 40. Yet considering that Marriott has better quarterly revenue growth, industry-leading margins, RevPAR growth that will keep driving higher revenue and income, and one of the most solid international expansion plans of the three hotel brands, Marriott still looks like the best play in this industry right now.