I just started noticing this recently. It’s a nice touch. Before, you would have to go into a specific comment moderation page to keep track of comments. Now, it’s all tied into your profile page, just like when someone likes or comments on your status updates.
Months ago, I converted my commenting system to Facebook’s. I had my reservations before. Most of it is that because it’s javascript based, the comments will not be crawled by Google. All Google sees is the javascript code, not the actual comments.
The LA Times reported that the world’s largest social network Facebook filed papers for its IPO today. Here are some stats from the article: “845 million users; 483 million daily users; annual revenue of $3.7 billion; $1.8 billion in operating income and $1 billion net income.”
It didn’t mention the number of users in the U.S. though, which is more important. Oversea traffic is cheaper and harder to monetize, even though that’s where most of Facebook’s growth is coming from.