Seven Entrepreneurs Who Bootstrapped Their Way To Success
flowtown.com
flowtown.com
according to wikipedia, 'Bootstrapping ... a self-sustaining process that proceeds without external help'.
http://en.wikipedia.org/wiki/Bootstrapping
I fail to see how either Twitter or YouTube fall under that classification. Both the companies needed outside investment to continue operating, and YouTube was not profitable when it was bought by Google. Therefore they were getting external funding. Twitter too has been taking external funding.
I don't believe that Napster was ever profitable.
I don't know about the other companies.
Edit: and YouTube? If you upvoted this you didn't read it OR you wrote it.