https://blogs.scientificamerican.com/at-scientific-american/scientific-american-launches-new-paywall/

On August 28, 1845, the first issue of Scientific American described the editors’ desire to provide readers “who delight in the development of those beauties of Nature, which consist in the laws of Mechanics, Chemistry, and other branches of Natural Philosophy—with a paper that will instruct while it diverts or amuses them, and will retain its excellence and value, when political and ordinary newspapers are thrown aside and forgotten.”

Today, with award-winning features, news, commentary and visual-storytelling—including articles by more than 200 Nobel Prize winners and other distinguished experts—Scientific American continues to deliver unique insights about the ways that science changes our understanding of the world and shapes our lives. But in order to retain its excellence and value for another 175 years, the magazine must evolve. That is why, beginning April 15, we are launching a paywall on our website. Going forward, readers will be allowed access to three complimentary articles* per month before they are asked to subscribe to any of one Scientific American’s print or digital titles to read further. That includes the flagship monthly edition, one of our bimonthly anthologies (Scientific American Mind, Scientific American Space & Physics and Scientific American Health & Medicine) or our five yearly Collector’s Editions.