Thousands of senior citizens across the United States are finding a profitable side hustle --- opening up their homes to strangers on Airbnb.

Nearly 78,000 seniors (ages 60 and up) across the U.S. shared their homes on Airbnb in 2017 -- accounting for $700 million in earnings, the company reports.

The typical host earned an extra $7,000 in income a year -- a positive boost for people living on fixed incomes.

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Airbnb is a website that allows people to open up their homes for vacation rentals or short-term leasing. There are over 5 million homes listed on Airbnb in over 81,000 cities.

According to Airbnb's annual survey, 41 percent of seniors reported that hosting their home has helped them afford to stay in their homes -- places they've often lived most of their lives.

Airbnb states that 45 percent of senior hosts rely on that extra income to make ends meet and spend it on important costs of living.

Senior hosts are beloved on Airbnb, the company said.

88 percent of trips hosted by seniors last year resulted in 5-star reviews.

Percentage of active listings with senior Airbnb hosts 

Typical host earnings for seniors by state 

Percentage of senior host reviews with 5-stars