Inasmuch the main utility of a formal living room is to entertain visiting guests, a WebRTC allows guests to initiate a communication session with the subscriber of the app that utilizes WebRTC.
Many go to enormous lengths to furnish and decorate a living space normally called Living Room. Notwithstanding the expense involved and the name, it is used mostly when guests are visiting. When we are entertaining guests and they are using the amenities in that room, there is no question of whether the guests have similar room and similar amenities in their houses. The only requirement is that they visit you and that you are ready to host them.
So is the case with WebRTC apps. The main reason for the app and for you to sign up for one is so people can initiate communication session with you. The only requirements are that your guests have a compatible browser and that you are willing to communicate with them.
Just because you have a lavish formal Living room does not mean that when you visit one of your friends you will experience similar luxury. Similarly, subscribing to a WebRTC app may not imply that you can initiate a communication session to one of your friends. In this respect, WebRTC apps for for receiving only. This is critical. Anyone suggesting differently is misleading you.
The image is courtesy of AvaLiving.com