I am beginning a health/weight loss list from paid traffic. I want to regularly offer them valuable free content along with my affiliate marketing promos. I have much knowledge in this field, but no quality media infographics, videos, etc that would give my list real valuable info free. First are these things called lead magnets? And second, where can I get magnets and/or free valuable content? Do I have to create it? Can I use online infographics like from NIH, CDC, etc?