Don't forget Hipchat/Slack - IM How about putting emphasis on "have to" instead? For most people, the advantage of these services is that you get very good se

Don't forget Hipchat/Slack - IM How about putting emphasis on "have to" instead? For most people, the advantage of these services is that you get very good services for little cost. It's simply cheaper to use 3rd party services. That why they've become so popular.