The idea is pretty simple:
Before reaching out to your prospect list, research who their competitors are. You can do this by searching for “brand + alternative” or “brand competitors.” You can also look in Ahrefs competing sites (though they might not always consider these direct competitors).
After you have a list of their competitors, check out their top page in Ahrefs or if you don’t have Ahrefs, look at the competitors’ popular posts in their blog sidebar or footer.
➜ So what’s the idea? You reach out to the site saying that their competitor has an article on “X” that they don’t and that you can write one that’s better for them.
Hence, the Jealous link-building strategy.
…get their interest by telling them that you can outrank their competitor with a blog they don’t yet have. Heck, if you have a secondary site, you can sweeten the deal by linking to that post.