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.
AAdvantage is the frequent flyer program for American Airlines. It was launched on May 1, 1981, and it remains the largest frequent flyer program with over 67 million members as of 2011. Miles accumulated in the program allow members to redeem tickets, upgrade service class, or obtain free or discounted car rentals, hotel stays, merchandise, or other products and services through partners. The most active members, based on the amount and price of travel booked, are designated AAdvantage Gold, AAdvantage Platinum, AAdvantage Platinum Pro, and AAdvantage Executive Platinum elite members, with privileges such as separate check-in, priority upgrade and standby processing, or free upgrades. They also receive similar privileges from AA's partner airlines, particularly those in oneworld.
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.