As far as consignment, it is suggested that you have a few events lined up in a row before getting it so that you aren't stuck with it. I haven't done consignment, anyway, so I am no pro on that subject. I have placed a few orders that got me some inventory because I love doing booth events. I just collect inventory slowly for those and it works out fine. Whatever I don't sell one month, no biggie, I just save it for the next one.
I've never had a problem with customer service, either...sorry you had that. I have made a few mistakes in my orders and they were taken care of right away with a simple phone call.
I did have two events lined up following the bookfair; a Halloween "open house" for local businesses (lots of people looked and took info- no one bought anything or contacted me for more info), and then a Christmas Bazaar (I paid $25 for the space and then sold a whopping $40 in books). I agree the books are great and showing them to people, even selling them, is fun, but it doesn't compute into profit in any way.
Usborne just contacted me out of the blue, six months after I "quit". They sent me a bill for $106 in consigned inventory that they supposedly didn't get back though I mailed it over six months ago and they already charged me the restocking fee. Its kind of hard to follow up on that since I got that inventory 8 months ago and no longer have access to their website since I didn't pay to renew it. I'm still going with scam and ripoff. Again, just my personal experience and opinion, and so glad I can share it here!