Let's congratulate Kevin Rose on his first day as a Googler. The founder of Digg, a popular online content aggregator, was hired away from his latest start-up endeavor for as-yet-undisclosed work at Google (Nasdaq: GOOG). The hiring could have serious ramifications for the ongoing Plus-versus-Facebook battle that Google seems to be losing. It might also mean very little. Much will depend on Rose's role inside the Googleplex, and his ability to identify or create buzz around hot new online properties.

Can you Digg it?
A little background: Digg's been around since 2004 and was an early site in the race to harness social feedback. Users submit news articles, videos, random links of interest, and the like, and the Digg user base can vote on their popularity. This probably sounds exactly like the more popular Reddit -- because it is. Although Reddit came later, that site's now raced ahead of Digg in popularity, according to traffic-analytics sites Quantcast and Alexa.

Google expressed interest in buying Digg in 2008 for around $200 million but decided against it. Google was also an early venture-capital partner in Rose's current (now closed) startup, so the relationship between the two parties is both long-standing and ongoing. However, Rose's Digg tenure was a bit fraught, as he held the CEO position for only a few months in 2010.

Rose to the occasion
Rose's function within the 'Plex is unknown so far. The easy speculation, as I mentioned earlier, points toward building up Google+, which has been dogged by low engagement numbers in spite of a rather fast ramp-up.

But Rose's impact on Google's social ambitions may not be as important as his ability to zero in on great startups. The list of his startup investments reads like a Who's Who of buzzworthy online names: Path, Zynga (Nasdaq: ZNGA), Square, Foursquare, Twitter, and recent mobile-app superstar studio OMGPOP (of Draw Something fame) have all gotten funding from Rose. While you might debate the merit of these companies' business models, there's no doubt that they've grown tremendously and in many cases represent logical extensions of Google's social-focused business model.

Sometimes you build 'em, and sometimes you buy 'em. Which will Rose be best with? Google watchers might not have long to find out. If you'd like to be like Kevin Rose and find the best companies before they blow up (in a good way), take a look at The Motley Fool's new report on the next great multibagger. It's already given huge gains to our Motley Fool Stock Advisor subscribers, but there's a lot of room left to grow. Don't miss out on the opportunity -- reserve your free copy of this important report now.