- offer bug updates for v.2 existing customers with no additional feature development
- offer a paid upgrade with lower subscription for existing customers
- offer more affordable iphone-only or ipad-only subscriptions (currently it's $40/year for a suite of iphone, desktop, ipad apps)
- offer an ad-free v.3 upgrade locked to v.2 features to existing customers
- offer a v.3 upgrade requiring existing customer to make an informed choice vs. forcing it as an upgrade replacing their their current, paid for app with another one nagging them for subscription.
I spent 1 minute on these options, as an amateur in the field, and they all sound like viable possibilities for increasing revenue while retaining respectful trusting relationship with existing paying customers.