Google+ launched brand pages six months ago, introducing new social lingo, including "hangouts," "circles" and "+1s." But strike up a conversation with a digital marketer these days, and talk of "+1s" has been replaced by that of "pins."

Rather than challenge Facebook and Twitter for mindshare, Google is a distant fourth to Pinterest, with its "pin it" button now appearing alongside Facebook, Twitter and email buttons on prime web real-estate such as eBay and Amazon product pages.

Still, Google is continuing to double down on the investment from both a product and a marketing standpoint. It has rolled out seven unique TV spots to promote the platform since December, according to Ace Metrix, which tracks and evaluates ad creative and, earlier this month, launched an iPhone app and the ability for any user to set up a "hangout on air" to broadcast video chats to an unlimited audience.