It’s like when you’re at a noisy party and it’s hard to hear the person talking to you 2 feet away, but suddenly you say something awkward and the room quiets down. Now everyone can hear you. The same is true with the internet. When there is less other noise to compete with (ie fewer Tweets, emails, blog posts, etc) your content can gain attention more easily.
Via Steve Law, ABroaderView, Martin (Marty) Smith