This isn't a terribly new story, though this is the lowest price I've seen yet. The spec is vaguely plausible for the price: 8 inch 2-point capacitive touch screen, VIA8650 CPU, Android 2.2, 256MB RAM, 2GB ROM, WiFi, 1.3 MP camera. The promise of 'internal Word and Excel' is a nice selling point, though.
I suspect the performance for this would be horrible at best, and good luck getting many recent Android apps to run (did 2.2 have the Fragments API?), though it will do fine for web and video. Indeed, video is a major use case for such things. The battery life is quoted as 5-6 hours and that probably means standby life. But in emerging markets, if you only HAVE $50 to spend, this might be your first internet experience outside of an internet café. And depending on who you talk to, there could be well over 100m similar devices being made in China this year.
However, it hardly needs pointing out that including such devices in global 'tablet' sales for the purposes of calculating the market share of Apple, Samsung or Amazon products will create a rather misleading impression.
Incidentally, you could get 100 of these (the minimum order) for the price of four Surface Pros.