How internet is used to advertise?

Nearly all artists advertise them selves using the internet is an easier way to get through to the audience. artist such as Lilly Allen have websites which advertise themselves and their music, the site includes music videos, pictures, tour dates, blogs and many links to myspace, Facebook, youtube, bebo, radio and to many other sites. They promote their unsigned albums on youtube or myspace etc. to get their audience feedback and advertise the albums before it is published out to the industry. An advantage of using the internet as a source of advertisement is that it doesn't cost them anything to use the internet so its free, its is also a good way for the audience as it is free for them and easier to use and get through to, to get the most recent updates.