When I sold through them as a vendor I remember Fab being extremely inefficient in nearly everything they did. I had to email a good 3-5 people to get anything done because nothing was automated. From shipments to payments to setting up the sale to uploading media and printing out orders and postage. Everything was done manually by emailing someone and yes there were mistakes.
I had to use excel, save the file they emailed, and email it back to them just to set up a proposal for a sale. Yes, Microsoft Excel. And they sent any type of instructions in PDF formats.
They also used some really expensive shipping options even though I had cheaper alternatives and was doing fulfillment myself. I had to manually sign up for a UPS account and get approved to have them charged and all sorts of nonsense. They also wanted me to set up a UPS pick up ($8) every day. With their margins I just don't understand how they made money. Apparently they weren't which is why things got bad.
And their marketing was just such a waste at times. They'd mail a 3 sided folded postcard on extremely thick paper with only 3 random items on it (that weren't even interesting) and their "Fab, Smile, you're designed to" logo. They did a terrible job advertising and it all lacked thoughtfulness.
Their in-house fulfillment team used custom boxes that were printed in all BLACK ink and on top of that had printing on the inside with their logos and catch phrase on the inside and out. I have never in my life seen shipping boxes that expensive used to ship an item.
EDIT: I'm not saying they weren't nice to work with, they were all extremely pleasant, just the system of doing things was very inefficient. Rather than emailing me so many different forms and PDF instructions they could have linked to them on the FAB control panel. It's the CEOs job of ensuring the systems a business uses are efficient and it seems that's what destroyed them. Wasting money.