what happened? well, we really feel like twitter has come of age over the last year, that the ubuiqity of the platform everywhere and again, twitter is also an enterprise in the business that has become a platform for others to innovate on marketing messages, human rights messages all kinds of different communications that are happening via that twitter platform. and twitter, itself, is evolving as a business. it s generating real revenue, finding ways to turn what has been a terrific utility for consumers into something that also is a viable and strong business. and one of your sub categories is mobile and this is an area i believe is part of the future. so four square is at the top of that list. explain. well, four square is a much smaller company than some of the other ones, at least in the scale of its users and the scale of its business right now. but with four square, allows you to check in to certain locations and to use geo location, a combination of gps positioning