We may live in a mobile-obsessed world, but it turns out the best-selling consumer-electronics gadget on Amazon isn't made by Apple or Samsung. Neither is it a Kindle—which is kind of shocking, given that Amazon promotes its own tablets and e-readers right on its own home page.

The winner is … Chromecast, the tiny Google device that streams video and music to a TV. Chromecast has topped several of Amazon's bestseller lists—including the biggie, its list of all electronics—for weeks now, displacing a Kindle model as sales leader and leapfrogging ahead of both Apple TV and the Roku.

The two-month-old Chromecast currently tops the charts for every Amazon subcategory it's listed in, including digital media devices, streaming media players and televisions and video. The next most popular TV streaming devices in the general electronics rankings are the Apple TV (at #7) and the Roku 3 (at #8).

It's easy enough to guess why the Chromecast is popular. First, it's cheap—$35 for a gadget with functionality similar to other streaming devices in the $50 to $100 range. Second, when it debuted, Chromecast immediately sold out—at the Google Play store, at Amazon, and at other retailers. Whether that was by design or due to inept supply chain management isn't clear, but one consequence was that Chromecast took on the allure of a hot, in-demand item.

Perhaps most important, Chromecast isn't restricted to a single platform. Although it's produced by Google, Chromecast works for both iPhone/iPad and Android users, at least for the most part, which gives almost anyone with a smartphone, tablet or computer the opportunity to stream to their TV using devices they already know and use. In other words, there's virtually no learning curve.

Chromecast's sales success does suggest that mainstream users aren't too concerned about the lack of streaming options—to date, only two non-Google services, Netflix and Hulu, work directly with Chromecast—or the wait for more apps to emerge. At least not yet. 

My Chromecast Lies Over The Ocean—Oh, Wait

Right now, some potential customers may be more concerned about the fact that Amazon has apparently stopped shipping the Chromecast outside the U.S.

While Google hasn't yet opened up product distribution outside the U.S., earlier this week, Amazon indicated that it would ship the device to select international destinations. Shoppers in Europe, Asia and Australia reported success in ordering the device. But now, Amazon's Chromecast product listing reads: "Currently, item can be shipped only within the U.S. and to APO/FPO addresses." 

I've reached out to Amazon for comment, and will update this post if the company responds. 

Google might want to enjoy Chromecast's sales leadership while it lasts. In the future, would-be customers could get put off if the wait for more compatible apps and streaming sources drags on. Before long, Chromecast may also have a new challenger: Amazon's rumored streaming gadget. Possibly dubbed the Firetube, the device will reportedly launch in time for the holiday season. 

When and if that gadget debuts, Amazon is likely to promote the heck out of it—and that could be bad news for Chromecast's reign on the bestseller list. 

Images courtesy of Amazon