If you are truly interested in user engagement you would have a section titled 'What do you like least about All My Books. This item is little more than a publicity vehicle.
I have used the software for a few years now and am mostly happy , however I have one major issue, the lack of a professional, ticket based, customer support service. I have tried to report issues through the contact form, however the result has been unsatisfactory. All I get is an anodyne response, we will investigate and see what we can do. I have never seen a change implemented that addresses any of my concerns.
I am being sent emails encouraging me to spend money for a new version, but sorry, until the support culture is improved and real change is delivered then I am unlikely to spend more money with you guys.