Do you visit only one site on the Internet? I just wonder how far you're willing to go here, because the beauty of the internet, to me, is that there are zillions of sites on lots of different topics.
As time goes on, the number has certainly decreased. Look at how popular rss ands sites like reddit are.
In fact, in terms of my actual daily "rotation" of sites, there are exactly 3: Reddit, HN, and Gmail.
I absolutely want to visit less sites. Stack-Exchange as a product for me would have significantly more value to me as an integrated network, rather than the current mish-mash of partitioned off sites. Let me search all questions, let all questions (in tags I don't have filtered, and of subject areas I've added) appear in my questions list.
