Answer:
We can earn money by designing and developing Themes and Plugins for WordPress users without any investment and domain name.
Step-by-step explanation:
WordPress is the open source platforms where any one can add or edit themes and plugins. Peoples who are using WordPress needs new themes and plugins to enhance their websites in terms of new look and functionalities.
As we mentioned that, WordPress is an open source platform, so any one can add, edit new features in the WordPress platforms. These features included plugins and themes that designers and developers make and sale on WordPress platform and earn handsome money. For this purpose they don't need any investment and domain name.