I think, that it's useful to paste some info (at the moment I wrote it, I was a little bit nervous):
From Apple:
"Available on macOS Mojave
When users on macOS Mojave first open a notarized app, installer package, or disk image, they’ll see a more streamlined Gatekeeper dialog and have confidence that it is not known malware.
Note that in an upcoming release of macOS, Gatekeeper will require Developer ID signed software to be notarized by Apple."
You have to NOTARIZE your EXISTING (already) software, for your new customers running macOS Mojave in order they to can use it!? NOTARIZATION, lets say that (just) attaches a ticked to your already SIGNED software - (NOTARIZATION) not useful software functuanality for the customer that involves time and effort!!! By my information macOS Mojave requires and allows only 64bit apps... I will postpone its usage to the end of the world where that depends by me. It is Apple commercial policy imposing the usage just of their own products against all native cross-platform technologies, destroing businesses and in this way against the reqular Mac Users, but without posts like this They will never know!
With other words: The Customer can not update to the latest software versions, because Apple disallowed 32bit apps store submitions and the native cross-platform development environment vendors are still not ready with the 64bit compilers and graphical user interfaces. According to their Road Map, they will be ready at the end of 2019. AND Because of the GateKeeper the software (in Apple store) can not be downloaded by the new Customer... But the taxes are paid!