I'm sure AT&T, Verizon and others appreciate your support. I can never get the "stream everything from the cloud" sentiment ("it's the future" or not) when our connection to the cloud is through ever-tightening tiered data plans by the likes of AT&T or similar. Those who can be in free wifi zones most of the time probably get by just fine. Those streaming meaningful amounts of data over cellular networks are likely streaming extra dollars out of their wallets too.
Personally, I'd much rather sync it to bigger storage and stream sparingly than give the money to AT&T, etc so that I can have ready access to my own media. A solution like this would make it possible to load up a bunch of media for a long trip and rarely burn cellular data for my own media. For example, if I was taking a long vacation, I might load 1+ of these cards with movies to fill the time while traveling. If I went the other way- streaming my media- I'd quickly roll into higher tiers at more cost and it wouldn't take long for that cost to exceed what it costs for 1+ of these cards.
But I'm glad streaming works for you.