RxJS and Observables didn't arrive just to be a one-to-one match to Promises. RxJS and reactive programming arrived to promote a different kind of architecture, as well. From such an architecture emerged a store pattern suitable for services. The store pattern is about ensuring our service is stateful and can deal with data coming from more places than HTTP. The potential places where data can arrive from could be, for example:

• HTTP
• localStorage
• Sockets
• Firebase