Well, that one is debatable, and it would be a nice problem to have. The cool thing about Reddit-type functionality is that countless posts is not really a problem; the better stuff always bubbles to the top. It's completely the opposite with Twitter. The more people that post, the messier it gets and the stuff that gets bubbled to the top tends to be the stuff the least informed but funniest and highest follower count posters post or promote. Many times, your follower count is in inverse relation to your intelligence and value add.