Airbnb is an online marketplace which connects hosts and guests all over the world. Our inventory includes over 4.5 million listings, which enable the travel of over 300 million guests. The growth team at Airbnb is responsible for helping travelers find Airbnb, in part by participating in ad auctions on major search platforms such as Google and Bing. In this talk, we will describe how ad- vertising efficiently on these platforms requires solving several information retrieval and machine learning problems, including query understanding, click value estimation, and realtime pacing of our expenditure.

Communication services are increasingly customized to meet specific usage contexts. An example of such customization is to tailor the user experience differently when the services are accessed for personal reasons than for a professional usage. Users may also own multiple devices and choose to optimize their interaction with the services for each device. This paper describes a system which uses identity as a key element in delivering such converged contextual services. A method based on reverse auctions strategies to select the best service provider given a set of user preferences is proposed. The system leverages the IMS identity framework and complies with the liberty alliance standards for federated identity management, hence giving access to a wide range of personalized services.

A variety of wireless access technologies provides todaypsilas users with pervasive access to critical content and applications. Guaranteeing a satisfactory quality of service requires reliable and ubiquitous delivery schemes that optimally use the available access technologies. This paper presents a novel architecture to support adaptive real-time data and multimedia applications over different wireless technologies. It addresses several issues associated with the satisfactory operation of applications running over heterogeneous networks. The system is validated using a real-life healthcare application capable of transmitting voice, video and medical data simultaneously. Experimental results are reported that demonstrate the viability of the approach.