There are many profits making business in US, but at the same time least profitable business also exist. There are various reasons for the organizations that are making marninal to no profits.
Every non-profit organization are least profitable. They exist for the betterment of human goods and does not involved in business for the purpose of making profit. In US there are many non- profit organization which are working and are making less profit. For example many CCRCs (Continuing Care Retirement Communities) and Assisted Living Facilities are run as non profits which turn on average a -1.0% profit margin. Some organization like hospitals, schools and many other institutions has to run in charity for the benefit of the people in US. They are existing for the betterment of the society. Schools and other institution are engaging themselves to created educated people for the huge employment opportunity in US. This type of organization is serving the society without looking for the profit. The non-profit organization is providing facility to the people and to provide better facility they are incurring less profit.