If you have a way with words and know how to make the keyword-friendly, beautifully designed, SEO-optimized landing pages, why not charge other companies for your services and turn it into a money-making side business idea? Even a short landing page is worth a couple hundred bucks in most cases, and so much more if you know how to pitch your prospects well. If you want to get started with your business idea of becoming a landing page specialist or freelance copywriter, check out Len Smith and Sean Kaye's awesome course on Udemy, Copywriting Secrets: How to Write Copy That Sells.
My 10-year-old son brought home a book from our park’s free library box. It was a biology textbook – teachers edition. He said it looked interesting and hey, it was free (having no idea you could sell it). I scanned it in my Amazon seller app and realized it was worth around $150. He was so excited. We listed it for sale for $130 and it sold! Going to tell him, he just made $130!