The amount of time taken to install your application and then get it configured for live use by your customers is a critical part of your customer relationship. They are obviously keen to get their hands on your new and improved releases as quickly as possible. Careful planning and awareness of the components you are using support packaging, and are upgradeable, are important, as these things impact the effort involved in going live with your application.
When exploring the various platform features available to you, it is important to check whether the related component types can be packaged or not. For a full list of components that can be packaged, you can use the Metadata Coverage report at https://developer.salesforce.com/docs/metadata-coverage.