Apple Pay hasn't flopped where? Actually it's the first time I here about its existence. So if it's not just 2 weeks old I strongly assume that it in fact has flopped. I have an iphone 6s currently btw.
I see it advertised a lot and the biggest kiosk chain in Switzerland accepts it. But I don't know anyone who uses it apart from some overheard conversations on the tram. Totally anecdotal, though. I don't think Apple releases numbers.