My company used WebEx and I could make it dial me and start up my conference line without having to go through all the regular pin entry stuff. Now we're using Lync (Skype for business) which is similar although tragically buggy. That can also dial me and sends notifications if you hook it up.
The key for these kind of apps is cost and reliability. Seems like they're advertising substantial cost reductions and better quality. If either one is true they'll likely make out really well.