There was a Forbes article on HN about Chris Sacca yesterday, and he's talking about it now - https://www.periscope.tv/w/VvV_yzk2fDY0OTI3wusAmiDk5lk8euhHx.... I think it's pretty interesting, like a live AMA.

EDIT: It's over now. It's certainly an interesting platform, and I do think it will catch on if celebrities start doing these types of AMA talks. Personally, I would love to watch someone like Sam, PG, or Fred Wilson do one.