A niche edit is when your link is added into an existing article on a site, instead of publishing a brand new guest post.
The good version is simple: find an article that already ranks, already has topical relevance, and has a paragraph where your link genuinely adds context. The anchor should read naturally in the sentence, and the target page should match the topic closely.
The bad version is where people force anchors into random old posts just because the domain has a decent DR. That usually looks obvious, and it is where niche edits get a bad reputation.
Things I would check before buying one:
Relevance of the exact article, not just the website.
Whether the page gets traffic or ranks for real keywords.
Anchor fit. Exact match is not always best.
Outbound link quality on the page and site.
Whether the edit looks editorial or randomly stuffed in.
A niche edit can be stronger than a guest post if the page is already trusted and relevant. But if it is just a paid link jammed into an unrelated article, I would avoid it.