What is someone going to stop doing when they start using your product?
Jason Fried

A better question to ask, especially for rationalizing a product, is “how would this product improve or add quality to the user’s lives?”. The product needs to have an aspiration and an ambition to develop a pathway/s towards that realization. This pathway will have obstacles that need to be overcome (competition, challenges in communicating it to potential users, irrelevant/redundancy when it’s ready for use etc.). Who are it’s supporters and obstructors? How does the contextual or operational environment accept it? Does it build on something that is known and used? So rather than finding out what people will stop doing. (They may be doing more if they start using your product) it would be better to find out how the product adds ‘quality’ to their lives…I trust that this makes sense. Thank you for the post and sharing.