People can get Alexa skills through four methods:
Through the Alexa Skill Stores
Every region Alexa is in has its own Skill Store. When you publish your Alexa skill to a particular Skill Store, your skill becomes available in that region. When a user searches for your skill in that skill store's 'Alexa skills' section, they can enable it!
Through the 'Skills' section on the Alexa mobile app
Users can enable skills through their Alexa mobile apps in the skills section. This is a mobile version of the skills store found on Amazon's website, and allows users to search for and enable your skill.
Asking Alexa to enable your skill
Users can enable your skill through asking Alexa to enable your skill by name. If your skill is called 'Storyflow', users can say 'Alexa, enable Storyflow' which will enable the skill.
[Coming soon] Automatic enable
In the future, users will be able to enable skills simply by asking for a task to be done. For example, if the user asks Alexa to order them a pizza and your skill is for pizza ordering, Alexa may automatically enable and use your skill for the user.