google stock, Google chromecast, Songza

Google is giving away 90 days of Google Play Music All Access to Chromecast customers through Sept. 30. Credit: Google

Exactly one year ago last Thursday, Google (NASDAQ:GOOG)(NASDAQ:GOOGL) pleasantly surprised the tech world when it unveiled Chromecast. Since then, Google has sold millions of the easy-to-use media-streaming dongles, which the search giant last month confirmed "consistently outsell all other streaming devices combined at major retail channels."

Chromecast's birthday gift (to you)
In celebration of that success, Google is now offering all new and current Chromecast owners a free 90-day subscription to its $9.99 per month Google Play Music All Access service -- that is, as long as you sign up between now and the end of September and haven't had a free trial before. When you include the otherwise $30 dollar subscription, Chromecast customers can technically enjoy a real cost for their device of only $5.

Music All Access, for its part, is Google's premium unlimited music streaming product, and gives you access to over 18 million titles, customized playlists, smart recommendations, and the ability to upload up to 20,000 songs from your personal library to the cloud for streaming access anywhere without syncing. 

And yes, this is reminiscent of the 90 day free trial of Netflix, which Google briefly offered last summer then quickly nixed due to "overwhelming demand" the day after Chromecast's launch. But considering Music All Access is one of Google's very own services, you can safely bet this offer will survive for the entire length of Google's promised duration.

Here's what's in it for Google
But this promotion also isn't entirely selfless. So what does Big G get in return?

First, while Google still doesn't specifically break down its overall Google Play revenue yet, a recent report from app data analytics firm AppAnnie stated Google Play app revenue jumped 140% year over year in the first quarter. Within that, however, Google Play games accounted for nearly 90% of the platform's total sales. And though Android gaming is set to continue serving as one of Google's key growth drivers going forward, this push to promote Music All Access marks a notable effort by Google to both diversify that stream and add fuel to Play's already-impressive fire.

Google stock, Google Play Music, Songza, Google Chromecast

Google could be using this promo to show off future integration of Songza feature in Google Play Music. Credit: Songza

Second, this could be a way to show off the fruits of Google's acquisition of Songza only a few weeks ago. Specifically, Songza's unique music curation platform aims to seamlessly provide listeners with context-appropriate music to match their moods or activities, and had earned a respectable following of roughly 5.5 million users since its founding a mere six years ago.

To be sure, Google stated at the time, "Over the coming months, we'll explore ways to bring what you love about Songza to Google Play Music." Of course, we haven't seen that integration happen just yet, but a lot can happen before all those free 90-day subscriptions to Music All Access expire.

In the end, I can't think of a better way for Google to show music aficionados what they're missing than by offering a hefty free trial of its premium music service on the world's best-selling media streaming device. But I'd love to hear what you think. Will you be lending an ear to Google Play Music All Access? Let me know in the comments below