"Yea, no prob Em. So what's going on out on the wild wild web today?"

"Oh, not much, Google says only 12.945 million pages have been updated today, quite slow, but fridays always are." With the size of the web surpassing 50 billion pages last year it became much more effective for webservers to just ping Google when a page updated than having Google have to crawl the whole thing every couple of months.