I've found these benefits:
- Works on all of my devices. If someone @mentions me, it'll notify my phone just like a text message and/or email me (unless I disable that). And I can reply from my phone's hipchat client.
- Chat rooms and 1-on-1 work seemlessly. Chat rooms can also be public or private.
- History is persistent and searchable.
- Sharing files is as easy as a click. Sharing screenshots/mockups/images is as easy as copy/paste (we use this a lot)
- On the right-hand side of the chat room there is a list of all links & files shared in the room that you can easily search through.
- You can have guest access in chat rooms.
-It integrates with github and other services so that when we do certain things with our repository, it will notify one of our chat rooms.
And a million other little things. There is no single feature that made me think "I must use HipChat, this is awesome.", but rather a bunch of minor things that "just worked" and fit nicely together into a great experience.
It's worth every penny.
This sounds like me being facetious, but it's a great morale booster for teams.
BTW, you don't have to share your entire screen just the app you want them to see.