User Stream conection limit



I am using Streaming API for an application i’m going to sell. So i need to be sure of the connections limitations of the User Stream API.

My question is :
Is there a limitation on the number of user stream by application? For example, can i have 5000 customers who each run an instance of my app at the same time with one or more User Stream by instance (considering that each stream use a different twitter account for loging) ?