Where will my customers buy or manage their goMobi subscription?

If you give your customers the ability to manage their own goMobi subscriptions (i.e. to create and change their own goMobi sites, versus managing content for them), your customers will manage their sites at OpenSRS' unbranded control panel at [your-reseller-id].domainadmin.com. This control panel is completely free of any OpenSRS branding.