There is no fixed number — what matters is off-domain mention density in your category, not your own article count.
[01]/ the data
What we found
Top-cited companies in our study had thousands of third-party mentions, not thousands of owned articles; owned content alone didn't correlate with citation.
[02]/ how to do it
Three steps
Prioritize a small number of deeply researched, schema-marked pages over volume.
Pursue third-party placement in parallel.
Measure citation rate, not article count, as the success metric.