Marc Hassenzahl states that you should design for user needs and emotions (why) before you consider the what and how of a product. Marc is not focused on the business side of design, but his guidelines have an impact on profitability as well.
In 10-20 lines explain how focusing on user needs and emotions can impact the Return on Investment of your design.
Example feelings: happy😍, confident👍, encourage😆
I would suggest the following two points how focusing on user needs and emotions can impact the Return on Investment of the design.
One is that users will invest their time and money for the products which are focused on their needs and emotions. As an example, I would like compare the two language apps to memorize English words (as a non native speaker) for a certain exam.
The app I loved motivated me as well as made me confident and happy. It visualise my progress how many new words I have learned. Also the app offers me several types of quizzes, prioritizing the words which I haven't memorized, to help them sink in me. I continued using the app till I pass the exam.
The app I didn't like discouraged me. Though it included many words I didn't know, it just showed the long sentences of definition of the words. So couldn't keep opening the app.
Another point is reducing the cost. By focusing users need and emotions, expenses/efforts to create unnecessary product would be avoided. It doesn't make sense to invest resources unless the product would be loved by the users.
Thus, focusing on user needs and emotions contribute to better ROI by encouraging users to invest more to the products and avoiding unnecessary costs to make unfavorable products.