Due to the growth of international end-users, in early 2012, Airbnb opened offices in Paris, Milan, Barcelona, Copenhagen, Moscow, and São Paulo. These openings were in addition to existing offices in San Francisco, London, Hamburg, and Berlin. In September 2013, the company announced that it would establish its European headquarters in Dublin. Prior to the 2012 Summer Olympics, Airbnb acquired London-based rival CrashPadder, subsequently adding 6,000 international listings to its existing inventory. This acquisition made Airbnb the largest lodging website in the United Kingdom.
Airbnb features a review system in which guests and hosts can rate each other after a stay. Hosts and guests are unable to see reviews until both have submitted a review or until the window to review has closed, a system which aims to improve accuracy and objectivity by removing fears that users will receive a negative review in retaliation if they write one. However, the truthfulness and impartiality of reviews may be adversely affected by concerns of future stays because prospective hosts may refuse to host a user who generally leaves negative reviews. In addition, the company's policy requires users to forego anonymity, which may also detract from users' willingness to leave negative reviews. These factors may damage the objectivity of the review system.
The two organizations from which American Airlines was originated were Robertson Aircraft Corporation and Colonial Air Transport. The former was first created in Missouri in 1921, with both being merged in 1929 into holding company The Aviation Corporation. This in turn, was made in 1930 into an operating company and rebranded as American Airways. In 1934, when new laws and attrition of mail contracts forced many airlines to reorganize, the corporation redid its routes into a connected system, and was renamed American Airlines. Between 1970 and 2000, the company grew into being an international carrier, purchasing Trans World Airlines in 2001.
Hosts provide prices and other details for their rental or event listings. Pricing is determined by the host, with recommendations from Airbnb. Hosts may be required to report income and pay income taxes on income received via Airbnb. In the US, homeowners who refinance their mortgages with some agencies are able to count income they earn from Airbnb rentals on their refinance loan applications.