Communicative Language Teaching

While I understand the purpose and the basis of communicative language teaching; to effectively promote communication in the target language, I am wondering actually how effective it is.
The article states several activities that promote communicative competence such as role playing, scrambled sentences, and language games. I know that in the classroom settings, this could perhaps be comfortable for the students, because they are all second language learners and the only person that has communicative competence is the teacher. Thus, the classroom setting could make communication more comfortable. But, I'm thinking about real world situations. Outside of the classroom, how effective could these games and activities for learners be? Because it is likely that in a controlled environment such as a classroom, the outcome would be great. However, outside of a controlled environment when virtually any such situation could arise, how effective would the controlled environment be?