Unless listings are archived locally, they are vulnerable to the whims of
ebay. I have heard reports of Stamp Category users losing thousands of listings because
ebay considered them to be "stale". Without backup, there is no recourse and may be no way to resurrect or resubmit older listings with new pricing. Some have reported that
ebay has mistakenly suspended or removed the wrong account. Getting listings and images back could be problematic.
Of the desktop listing management programs, SixBit is the safest alternative. Competitors now exist, but may or may not survive in the marketplace.
I have sales records going back more than ten years making it possible to identify long-time or repeat customers.