Erotica and porn: which has more tat

[condor]

I think of erotica as something sexy enough to keep you aroused without needing to touch yourself. However, there are very think books that I can read all the read all the way through without boredom seeping in. So: what percent of porn vids can you watch all the way through compared to erotic fiction: i.e. vids over 30 minutes and novels over 150 pages?