This is getting a lot of play: Hitwise has published some traffic numbers that show increases and decreases in traffic to Google subdomains in the wake of the introduction of Universal Search (feeding more vertical content into Google.com results).
The winners so far are YouTube and Google Maps. See Bill Tancer’s chart below:
Video is the only truly new content type being featured in Universal Search. Previously Maps, Books, News, etc. all showed up the in OneBox results at the top of the page. So it’s curious that Maps would show so much (20%) growth. But it also coincides with the introduction of Google’s StreetView and other mapping features, which received a great deal of PR-related coverage and so could account for some of the traffic boost to Maps.
It’s also interesting that Book Search is suffering. It was explicitly mentioned, as one of the great Google services that many people don’t know about, by Marissa Mayer during the Universal Search announcement.
Screenwerk 