Interesting, I find it hard to see how this wouldn't be annoying, but it looks pretty novel.

Interesting; it reminds me a little of an addon from maybe a dozen years ago that would do the same kind of thing but with fiction. So you'd be reading a post on Slashdot or whatever, and the addon would find a sequence of words that matched the start of one of the stories it had, and it would add a few words of that story. If you noticed, you could click on them to get more of the story, and if you kept clicking it would eventually replace the text of the whole page with the story. It was a really neat way of just stumbling across fiction. Wish I could remember the name of the addon. For some reason I think it was Australian, maybe put together by a university or an arts council or something?