Earlier this week, Chinese insurer Anbang Insurance Group Co. made a proposal to acquire Starwood Hotels (HOT) for a cool $12.8 billion.

It's not clear whether or not the deal will go through, especially considering Marriott International's (MAR - Get Report) bid to acquire Starwood for $12.2 billion was about to be closed.

But either way, Anbang's bid raises an interesting question: what does it see in the hotel industry? With the rising popularity of Airbnb, shouldn't Anbang be concerned about getting into hotels?

Starwood isn't the insurance firm's first foray into hospitality. Just days before the Starwood proposal, Anbang agreed to buy luxury hotel operator Strategic Hotels & Resorts Inc. for $6.5 billion. And in 2014 the firm bought the Waldorf Astoria hotel for almost $2 billion.

But with all of these purchases, shouldn't Anbang be concerned about Airbnb?

With more than 2 million listings in more than 190 countries now, and having served more than 60 million guests, Airbnb, which is valued at $25.5 billion, is a serious threat to the hotel industry.

According to a report from Boston University, in Austin, Texas, which is home to the largest supply of Airbnb rentals in the country, each 10% increase in Airbnb supply results in a 0.35% decrease in hotel room revenue, with overall hotel revenues there falling by 8% to 10% over the last few years because of Airbnb.

The report's authors -- Georgios Zervas, Davide Proserpio and John W. Byers -- found that lower-priced hotels and hotels that don't cater to business travel are the most affected by Airbnb. As a result of these impacts, the researchers found, hotels are reducing prices in an effort to stay competitive.

"Our work provides empirical evidence that the sharing economy is making inroads by successfully competing with, and acquiring market share from, incumbent firms," the report reads.

The report is bolstered Wall Street estimates for Airbnb's market share.

"We estimate they have low-single digit share of industry room nights," Morningstar analyst Dan Wasiolek said. "We and many others believe that Airbnb has both expanded the market and is taking some share from hotels (mainly lower-priced hotels)."

Nonetheless, hotel executives don't seem to be all that worried by these inroads, given who seems to be losing the most business to Airbnb. 

On "CBS This Morning" last year, Marriott CEO Arne Sorenson dismissed Airbnb as an "interesting experiment" and didn't seem to be threatened by it.

Sorenson and Anbang aren't necessarily being overly confident here.

"Airbnb will continue to be a competitive threat, but the other side of things is that traditional hotels offer amenities and services that Airbnb listings typically don't," Wasiolek said. "Anbang made the proposal because on a per-key basis, the offer appears attractive for them, and as the Chinese economy slows, investors there are looking for places to earn return on their investment."