Since the late 90's, when it started booming. So, about 12 years.
Before you all emerged from your mothers' wombs (14 years).
Eleven years NONSTOP? Holy expletive!For me, I've stayed on the internet at least 11 freaking years.
First time I used the internet was 2001. It was just e-mail and Pokemon.com at the time, and since I had no one to expect e-mails from, I spent probably twenty minutes or less on the computer each day. So... nine years, now.