As it ramps up for a public offering, Airbnb says that it's posted two straight years of profits. 

According to a company memo shared with TheStreet, Airbnb Inc. was profitable on an EBITDA basis, or earnings before interest, taxes, depreciation and amortization. The memo did not give any specific numbers, however.

Airbnb, a marketplace boasting than five million home listings worldwide, also said that by the end of the first quarter, there will have been over 500,000 guest arrivals in Airbnb listings since it was founded in 2008. While best known for vacation rentals, Airbnb has sought to expand its business lines into areas such as corporate travel and "experiences," or travel activities that a customer can book through Airbnb. More than 300,000 companies have used Airbnb to help manage their travel needs, the company said.

Airbnb hasn't specified a timeline for a public offering, but CEO Brian Chesky told Recode in May 2018 that the company will be "ready to IPO next year," although he pointed out that he didn't know if they would. 

Airbnb, which was valued at around $31 billion as of a 2017 fundraising round, is one of several high profile tech unicorns gearing up for a possible IPO in 2019. Others include Uber Technologies, Lyft Inc., Pinterest and Palantir, all valued in the tens of billions. However, complicating factors that could stall out some public offerings that had been planned for the early part of 2019 include the federal government shutdown that's delaying SEC review of IPO filings, and the volatile stock market.