What are some alternatives?
When comparing Lightstreamer and reep.io, you can also consider the following products
Socket.io - Realtime application framework (Node.JS server)
Volafile - Volafile.org offers real time filesharing and fast downloads without delays or annoying countdowns.
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.
Send Anywhere - Send whatever you want, wherever you want
PubNub - PubNub is a real-time messaging system for web and mobile apps that can handle API for all platforms and push messages to any device anywhere in the world in a fraction of a second without having to worry about proxies, firewalls or mobile drop-offs.
WeTransfer - WeTransfer is a free service to send big or small files from A to B.