A word of caution when using the subscription service for the pods, a lot of folks (myself included) have received faulty pods recently. They either are completely empty when they arrive (juice has leaked out), or they taste like burnt plastic. It's been two weeks without a response from customer service, and I have stopped using the juul all together due to the QC issues.
The liquid is really really good, so I don't think it's all that surprising. Unlike anything else on the market. What's surprising to me is that no manufacturer that I'm aware of has even come close to duplicating it. There are a some (subtle) claims out there involving salts nicotine but you have to wonder if anyone has seriously (= scientifically) made a major effort to clone it. Also surprising that JUUL doesn't sell the liquid outside the pods.
BTW, the pods are much cheaper from the company online, especially with autoship.
I posted about this a while back in JUUL Improved thread. The battery is much better but still many issues with the pods...and the price.