The phrase is generally inaccurate. If You need to invest in one particular to have the up coming one for free, it was not truly free. Same with goods you receive for filling out a study. "For free of charge" is usually additional precise in that it implies you won't https://drive.google.com/file/d/14hrpBHBebZB7SuXhV7sUnMwZIuxqpI1J/view?usp=sharing