"As Howard Rheingold says on the video teaser we published some days ago, he has been working on the creation of development of a lot of on line communities. Based on this experience (and with the security that not all of them are going to be successful), Rheingold explained the keys to build up a community with high probabilities to succeed. In my opinion, this video (this master class) is useful not only for those professionals interested on the field of e-Learning, but for any smart Internet user too."