I have to agree with Phil, 30ml is a lot if you don't like the juice. If I order 1 bottle and don't like it, I may never order from that site again. They should at least offer 10ml sizes, if not 3 or 5ml.
Bigger bottles would be nice too, like 100 or 120ml..
When JC first opened I ordered 2 bottles, at the time they were 15ml. One I liked, one I didn't. I was thinking OK, they must have some others I'll like, but also some I won't, even though they sound good to me. Was about to order more when they changed to 30ml, then while I was making up my mind Jim mentioned sample sizes would be available so I waited, then they closed (lol).
My advice is to go back to 15ml or go something like 10 and 30. If business is great, feel free to ignore me - but if it's slow, the reason is clear: it ain't your juice, it's the bottle size.