There used to be an online publisher called Associated Content (bought by Yahoo for $100M in 2010) that used freelancers to write SEO-optimized content.

I realized that I could write some code that would scrape various sources of financial data and generate articles about stock tickers. Managed to make some money before the articles got flagged as too similar to each other, but if I had put a little more effort into differentiating them, I probably could have made a pretty penny.