Some time ago I decided to enable Hacker News' noprocrast option with the default settings. I am allowed 20 minutes of time on Hacker News every three hours. I did this because I was spending too much time on the site, especially in the evenings in London when the conversation was active in Pacific Time.
What I expected to happen was that when I could read Hacker News, I'd be desperate to get through as many stories as possible to consume as much Hacker News as I could before my time was up. But the opposite happened.
I visit Hacker News and then I can't find anything interesting to read. Or one or two things will be worth it and the rest will be dross. I truly was procrastinating reading stuff that wasn't really interesting after all.
The other effect is that I've founded myself reading conversations before articles. Since I know that I can read an article at my leisure, but that I have 20 minutes to take part in a conversation I'll quickly go to the conversations that interest me, and leave the article for another time.
Overall, noprocrast has been a winner for me. The only thing that's suffered is my karma value.