nancylebov posts about a
bad experience with an Amazon vendor who had a 95% reliability rating and says
she will never again buy from anyone with less than a 98% rating. I suspect she is in the right ballpark for what the safe cutoff should be. I also placed a fairly large order with an
Amazon vendor with a 95% rating before Christmas, and not only did it never arrive but there was no response to my polite email enquiries asking if the order had ever been dispatched. Needless to say I've applied for a full refund from Amazon, and expect to get it. Looking through the Amazon
feedback pages for
Wessex Books Ltd / The Book Cupboard of Bristol, I find that their failure to reply to emails about disappearing orders is a recurrent theme (and in one or two cases the shop has actually posted grumpy responses to complaints from thwarted buyers, which would be amusing if they weren't so unprofessional).
So I reckon
nancylebov's cutoff point of 98% rather than 95% is about right. If they can't deliver a satisfactory service forty-nine times out of fifty, just don't risk your money with them.