Upside for Google's YouTube
Google offers growth in product listing ads and in YouTube, which Pitz said could be a $4.5 billion business as online video continues to expand. To put that growth forecast into perspective, Netflix is a $4.3 billion business, the analyst said, "with substantially lower growth relative to what Google could do on YouTube."
RBC Internet analyst Mark Mahaney also sees the potential for substantial opportunity for YouTube. "We've had a thesis building here that says TV ad budgets are going to migrate online. If that's true, YouTube and Google are the biggest beneficiary of it," he told CNBC.
Mahaney, who has an outperform rating on Google and an $840 price target, notes that on their last earnings call, Google management told the Street the top 100 advertisers were spending at least 50 percent more in 2012 than they did in 2011.
"That's a lot of growth," Mahaney said.
Monetizing digital ads still remains much harder than monetizing ads on traditional media platforms.
(Read More: Media Faces Dwindling Ad Dollars: Ex-Sirius XM CEO)