Hi,
ModuleGarden should allow purchaser to remove ModuleGarden Logo which is linked back to ModulesGarden website on every modules as I strongly believe, every files are encrypted has ModuleGarden's contact details as well as License Key start with ModuleGarden_XXXXXX and under Under Setup >> Addon Module, it has Modulesgarden's details is more than enough for branding purposes.
Some people might find helpful with ModulesGarden Logo which is linked back to ModulesGarden's website for support but I found it is annoying.
Regards,
Trung