I can last several videos if I feel like it resulting in 1-3 hours.
Who is the girl in your avatar? She is hot!
Like everything, if it's an addiction, it's not a good thing. Someone who does nothing but downloading porn and doesn't care about anything else (taking shower, cleaning the house, doing the groceries, ...) is addict.
I watch more porn than my friends (I suppose), but I stay healthy and sociable and my life isn't focused on porn. I spend more time learning japanese, working and going to the gym than watching porn.