In a while Kutcher will have over one million people that actively follow what he says or does. Making him continues mass media.
Due to the nature of the web we are all media and publishers. We might have fifteen minutes of fame, but very few people have access to a continues mass audience without necessary having something to say.
Somehow Twitter is growing very fast. This changes the numbers of followers and thus perspective.
Within some time it will be possible for some people to directly reach over 1 million people by just using their cellphone while waiting in a supermarket.
People are mass media.