Notes:
The context here is that all individuals participating in the communication can be identified and are available to meet. Also, that the type of information to be conveyed is appropriate to being conveyed in this manner. But, more importantly, the presumption is that some other form of communication would be used by default.
In my experience, people like talking – and don't need encouragement like this to do so. Only if there are impediments to talking (location, an organisational culture of forcing people to “write it down” or of using email) can I imagine this being a problem.
I more often find a different problem: people not recognising circumstances where face-to-face conversation is inapproriate.
For many things face-to-face conversation is the most efficient method of one-to-one (or of few-to-few or one-to-many) communication. It isn't so good at many-to-many, or with dealing with unidentified (or unavailable) recipiants. Nor is it a sufficient means of communicating detail (I'd like a record layout as well as a verbal description).
If the development team is dispersed in space or time, or detailed information needs to be conveyed, then other means of communication must be used.