While a lot of attention has been paid this week to Google’s new Nexus 7 tablet and its ostensible competition with the Amazon Kindle Fire rather than Apple’s iPad, these comparisons obscure what’s really happening here. Google’s tablet moves are really just part of a wider ecosystem strategy, one that pits Google Play against established and evolving competitors from Apple, Amazon, and Microsoft.

Google Play, in case you’re not familiar, started life as Android Market four years ago, and at the time it was centered solely on delivering apps for Google’s mobile platform. Over the years, however, Android Market evolved to include other content types and with the rebranding to the friendlier Play in March 2012, Google made it clear that it was taking on other digital content ecosystems. Since its inception, Google Play has provided access to Android apps, music, and eBooks, and rentable movies. And with an update from this week, it’s branched out into purchasable movies and TV shows and magazines.

If you’re familiar with Amazon’s and Apple’s digital content ecosystems, in particular, the parallels are obvious. (Microsoft also offers most of these content types, minus eBooks, though a recent alliance with NOOK should fill that gap.) The question, of course, is how Google stacks up with its more entrenched competitors.

Pretty well, I think. In fact, the decision to purchase, say, an Amazon Kindle Fire or a Google Nexus 7 should come down to your acceptance of either company’s ecosystems rather than to hardware specifications. There are two reasons for this. One, the hardware isn’t permanent: You’ll upgrade eventually, and with low-ball pricing of just $200 for both the Fire and Nexus 7, doing so is no longer an impediment. And two, while many content services cross over between the Fire and Nexus 7, in particular, since they’re both based on Android, some does not. Amazon’s streaming video service is only available on the Fire, currently, for example.

Apple and Microsoft exist outside of this Android world, of course, so the decision to go with either involves a rejection, at least, in part, of the Google and Amazon ecosystems. That said, Amazon’s superior Kindle eBook platform is available on all of its competitor’s devices, and there are other cross-overs, so it’s not a black and white decision across the board. But you’ll want to choose wisely, and with an eye towards the future.

So let’s see how Google Play really stacks up. Not so much with “numbers”—I’m sure the number of movies, say, in each service varies somewhat, but any of these companies provides a decent enough selection where that’s not really an issue—but rather with capabilities.

Apps

Amazon, Apple, Google, and Microsoft all offer tremendous app store experiences across a range of devices. Amazon and Google, of course, target Android (handsets and tablets) where Apple targets iOS (iPhone and iPad), and Microsoft targets Windows Phone 8 (handsets), and, soon, Windows RT (tablets) and Windows 8 (PCs and tablets). There’s little to say here, but Android obviously offers the most choice, and on the Nexus 7 you should be able to mix and match between both Google’s store (the wide open Play) and Amazon’s more closely curated selection (Amazon Appstore). Put simply, Android—and thus Google Play—has a pretty serious advantage when it comes to apps, and there doesn’t seem to be any end to that in sight. But users of any of these platforms will be well served by apps, I suspect, though the Windows 8/RT picture is currently a bit of a mystery.

Music

Amazon, Apple, Google, and Microsoft all offer excellent music stores, and each offers DRM-free music files that will play on any of the other platforms. For this reason, you’re free to mix and match and the truly compulsive should likewise feel free to shop around for the best price before buying any music online.

Amazon, Apple, and Google offer cloud-based music services that let you store your own collection in the cloud and then access them wirelessly. Amazon’s and Google’s are the most versatile, since you can actually stream content from the cloud to your device. Apple’s service, iTunes Match, is not free ($25 per year), but it also doesn’t require you to upload most of your collection, since Apple will “match” your songs to the songs in its own store (hence the name) and simply provide you with access. That said, you can’t really stream from iTunes Match: You must download the songs, though they can play as they’re downloaded.

Microsoft doesn’t (yet?) offer a cloud-based music service like that, but it does have Zune Music Pass, a $10 per month “all you eat” subscription service that provides access to its 20 million song library (soon to be 30 million) across a selection of your PCs, Windows Phones, Xbox 360s, and on the web. I happen to prefer Zune Music Pass to the other offerings, since ripping, buying, and then managing your own music collection is tedious. But opinions/needs vary, and those who have gone to great effort to manage their collections over time may think differently.

In any event, Google Play certainly offers a very similar music service to that of Amazon, and a viable and obvious competitor to Apple iTunes/iTunes Match. They do not offer a streaming service like Zune Music Pass, but any Android user has a choice of services like Pandora and Spotify (and many others) that can fill that bill.

TV shows

Google Play didn’t offer TV show purchasing until this week, so I downloaded a few shows to see how things stack up. Basically, Google is offering a bare bones service, with a pretty slim selection for now. There is usually a choice between HD ($2.99 per episode) and SD ($1.99 per episode) programming (as on the others) and Google, like Microsoft (currently), doesn’t appear to offer subtitles on its TV show content (as does Apple); it does, however, on some movie content (see below).

It’s worth mentioning that Google’s TV shows only work on Android handset or tablet … or the web. That latter bit is kind of odd—you literally view the shows on YouTube—and it means there’s no offline viewing at all unless you do use such a device. But with YouTube being available on some many set-top boxes, it does offer the possibility of watching 720p HD purchased TV shows on your TV. To test this, I logged onto to YouTube using my Google account on my Xbox 360. And … it didn’t work. My purchased videos don’t show up in this Xbox app (yet?), even though I’ve saved them for later viewing and it has a “Watch Later” section. Ah well.

(The purchased shows did pop up in the Google TV’s YouTube app. But they wouldn’t play there either. I also tried the Chrome browser in that system. Nope.)

Movies

Google has offered rentable movies for a while, and I had tested this before on a Samsung Galaxy Tab 7.0 tablet. New this week is the ability to purchase movies, and as with TV shows, and with other services like iTunes and Amazon Video, your purchased are stored in the cloud, can be streamed on demand (to devices and the web, as with TV shows), and can be downloaded to Android devices only.

Finding subtitled movies is possible but difficult: You need to use the web interface and look movie-by-movie. Most of the ones I looked at do not offer subtitles, but some, like “Cars” and “Mission: Impossible Ghost Protocol,” do. Some (new, “Wrath of the Titans,” and old, “Full Metal Jacket”) are available only for rental for some reason.

gplay_movies_02_subtitles
A Google Play Movie, complete with subtitles ... on the web, via YouTube.

Google, like Amazon, lets you rent a movie in one location (say, your tablet) but then watch it elsewhere (say, YouTube on the web). This is very interesting and much less restrictive than how movie rentals work on Apple’s iTunes.

As with movies, TV shows are available only on Android devices and the web.

Books

Compared to Amazon’s Kindle, Barnes & Nobles’ NOOK and even Apple’s woeful iBooks, Google Books is a bit of a newcomer and probably lags behind some of the competition from a content standpoint. (Or as Google noted at Day 1 of I/O 2012, the “largest eBook store in the world” … or whatever.) It’s not horrible, and while the web reading experience is passable, the device-based reading experience is pretty good, and roughly analogous to that in other eBook readers, with different font and view choices. (Google offers a Books app for iOS in addition to Android, and Google Books content can apparently work on various devices like Kobo and NOOK readers too.)

This is one area where Microsoft doesn’t really have any presence, though the supposition is that a future Windows RT-based NOOK tablet will make that happen, and to be fair, the Amazon Kindle app is already available on Windows Phone and Windows 8, though in both cases it supports not just books but periodicals.

Periodicals

Following in the footsteps of periodicals on iOS and Amazon’s Kindle platform, Google this week introduced support for interactive magazines through Google Play. It’s pretty restrictive: You must find and use the new Google Play Magazines app. (On the Kindle Fire, there’s an analogous Newsstand app, though I prefer how the Kindle app works on iOS, mixing and matching books and periodicals in the one app.)

If you’re familiar with magazines (or newspapers) on other platforms, there are no surprises here. You can browse through a magazine as if it were a mini PDF version of the print magazine, with page thumbnails at the bottom of the screen to aid navigation. This isn’t horrible, but on the 7-inch Android tablet I’m using, the text is often too small, and pinching and zooming over and over again gets old.

(Google Play Magazines do offer a nice table of contents pane you can spring up on the side, also aiding navigation.)

But as with Kindle periodicals, I prefer to use what Google calls the “View Text” mode, which reduces a finely-rendered magazine replica to its most basic, device-friendly form: Text and graphics. This works a lot like web browser plug-ins such as Readability. And it solves a very real performance issue that dogs the normal layout, at least on the tablet I currently use. I suspect the quad-core nature of the upcoming Google Nexus 7 tablet will help in that department.

There’s no way to view these magazines elsewhere, too, so you can’t view them even on the web.

Final thoughts

What we’re looking at here is a full-frontal assault from Google, which suddenly has amassed a massive content library that rivals the current two champions—Amazon and Apple—and steps a bit above what Microsoft offers, assuming you’re willing to pretend that much of that missing stuff can be made up with third party apps like Amazon Kindle or NOOK. We can debate the merits of different phone or tablet types all day, but as I’ve noted in the past, this is really a battle of ecosystems. And with this week’s Play improvements, Google’s digital content ecosystem is really coming together. The only thing holding it back now are some weird oversights—lackluster or nonexistent subtitles for video content—and a lack of content volume, if you will, again with its video selection. These things will only get better, and that means that picking an ecosystem is simply going to get harder going forward. Right now, I’d say that Amazon, Apple, Google, and Microsoft are all pretty well positioned.