It isn't like seeing trends now is different to seeing trends in a few hours given that you have to spend resources and time doubling down ...
So, when a trend hit or for whatever reason, a page started to receive traffic, you could see it right away, add a bunch of content to it and then almost magically, push up it's search engine result position to snowball the page. For topics such as "Tiger Woods Affair", recall notices, etc, it worked really well.
Generating pages with inadequate information is in the same vein as throwing crap at a wall to see what would stick. It could be thought of as SE spam, but when quickly and carefully built out it was just the way that Mahalo worked.