Actually I have thought about that, but I think that Kickstarter, Indiegogo etc. covers that already pretty well.
There is off course little bit risk for writers in case that campaign won't succeed. But because people already long blog postings just for the joy of writing, I think that it is not too big risk to take.
And the good part about our concept is that funders will get their story immediately when the campaign is over instead of waiting for some future release.
For the time being, my wife and I use Straight Talk ($45 mo = unlimited talk/text + around 1-1.5GB of data [it's unclear]) It's an AT&T MVNO, and no 4G, but it works for us, and is the cheapest option I could find. (We both have unlocked iPhones.)