In modern applications the end users want to get their data. They want it now, they want it up-to date. In fact it does not matter whether these are pure web application, native desktop installations or mobile apps: everybody wants his data now!
For .NET-minded developers there are a numbers of options to implement near-real-time push style communication from the server/the services to the clients/consumers. You can choose plain HTTP or the super-new WebSockets features available in .NET 4.5 together with Windows 8 and Windows Server 2012. But the coolest and increasingly popular approach is to use a new framework: ASP.NET SignalR.
Via William delmas