They are often considered somewhat cultish. The internet has become the source for supporting content. With the millions upon millions of websites, as well as on-line newspapers, journals, cultural information, etc., finding materials for a class can be relatively easy. Languages teachers in general are already quite adept at finding authentic materials and designing activities around them. The internet makes it that much easier to do so, and to let students take a hand in bringing the content into the classroom.
Students find and respond to specific information.
See Ann Salzamann's Grammar Exploration Activities , and The Internet TESL Journal , and WebQuest , for examples. A huge list of quizzes from the Internet TESL Journal. But knowledge of how to incorporate interactivity into on-line activities is slowly growing.