Upgrades can cause considerable customer pain in a variety of ways. Make certain yours doesn't.
Ongoing technology evolution motivates ripple upgrades. Detail these requirements carefully .
Don't ever screw up your customers' data during an upgrade.
Understand just how frequently your customers can absorb an upgrade. They may want an upgrade, but they may not be able to absorb one as quickly as you can create one.
It helps to have tools to assess upgrade readiness, upgrade impact, and whether or not you can easily remove any unnecessary or unused features.
All market adopter segments require a good upgrade.