I wonder about nuances of engagement on Periscope vs. Meerkat.
Periscope's saved video is touted as a feature, but I've noticed that because Meerkat does not give me this option, when I get a notification for a stream I want to watch, I hustle to engage because it's live and I don't want to miss it.
I have not used Periscope yet and will be checking it out, but I can absolutely envision a scenario where I get a Pscope notification and ignore it because there really is no urgency as it will be there later. And then those streams end up like just another article in my "read-it-later" apps. Saved and then forgotten because I've moved on, and the promise of what could be in that stream just isn't compelling enough to chase it down later. Saved video is what we already have everywhere all of the time.
My guess is that Meerkat's inability to save the stream could be the killer feature.