I think people try and say this about Facebook, SMS, & Twitter. It is a new form of permission marketing. That is why companies spend so much time on their face

I think people try and say this about Facebook, SMS, & Twitter. It is a new form of permission marketing. That is why companies spend so much time on their facebook page, and many do with twitter as well. They will not replace email marketing in the short term, but they reach a group of people that hate to give out their email, but aren't as afraid to follow or friend people.