I agree with that. Normally with newspapers there is nothing of interest to read after a certain amount of time spent reading. But on social news sites, an interesting article can appear anytime. It's basic operant conditioning. After a variable amount of time, you get the reinforcement of reading an interesting article. And the VR(variable reinforcement) schedule happens to be the most addictive. http://en.wikipedia.org/wiki/Reinforcement#Schedules_of_rein... And the Fixed Interval (FI) schedule, which sounds like what you are suggesting is also the least rewarding. So I think it's a great idea.