Competitors who've already built out extensive content libraries have often done a lot of long-tail discovery work for you, whether or not they realize it.
Look at Their Blog and Help Center Structure
The specific subtopics and questions a competitor's content addresses reveal the long-tail terms they've identified as worth targeting.
Check Their URL and Heading Patterns
Specific, descriptive URLs and headings often mirror the exact long-tail phrase a page was built to target.
Find the Gaps, Not Just the Overlaps
The more valuable insight is often what a competitor hasn't covered yet, which represents long-tail territory still open for you to claim.
Next step: Use the Longtail Keywords Tool to validate that a long-tail term you've spotted in a competitor's content has genuine search volume behind it.