Google itself says it is still years away from being able to monetize voice searches in the same way it does search, apps, ads and online transactions. Consequently, it’s not spending much time at the moment thinking of a business model for it and advertisers to exploit the opportunity, said Jason Spero, Google’s vp of performance media. “I think we have enough history from the apps world, the auctions world and the transactions [we do] that the combination of those will be the foundation of a business model for assistance when we get there,” he said. Here’s a look at the state of voice search advertising, in three charts. Get the full story at Digiday