Unethical. Exploitative. They ask you to complete assignments that benefits the company and get free work done. They have no intention of hiring you. I had an interview where the interviewer was very pleasing and sounded as if I was their dream candidate. Then they asked if I would complete an assignment after which they would discuss the onboarding formalities. The assignment was extremely detailed and was the kind of work you would get paid to do. However, I trusted these people and put considerable time into crafting out marketing strategies and plans for them. After the submission, they did not get back at all until I repeatedly reached out to them and they said they were not moving ahead.