Yeah was just thinking aloud. Elsat pointed out that highlighter.com offers subs to creators, but can't find out whether they actually work. From a function design perspective you want something with the least amount of efford for the user and as close to their existing frame of referrence as possible. Zap per post requires this shift in mindset that's quite high to overcome it seems...
There's also Fanfares but that makes more sense for larger pieces of content like audiobooks and such.
