Most replies focus on selling data or services, but nobody mentioned the legal risks. Scraping social media (FB, Reddit, LinkedIn) often violates their ToS, especially harvesting emails. You could get banned, sued, or worse if you sell that data.
Instead, target public datasets (gov sites, e-commerce prices, SEO metrics) where scraping is safer. Or anonymize/aggregate data to avoid privacy laws (GDPR, CCPA).
Also, consider API wrappers (e.g., scraping Amazon via Keepa’s API instead of brute-force bots). Less risk, more scalability.
TL;DR: Monetization isn’t just about what you scrape, but how and where you do it legally.