SISTRIX measured 82,619 ChatGPT prompts over 17 weeks and found that 74% of cited domains rotate out within seven days. This third-party finding shaped how the AnswerGraph panel was designed.
74% of cited domains rotate out within 7 days (SISTRIX, 82,619 prompts)
Single-run citation checks have 40%+ week-over-week variance
When ChatGPT and Perplexity are asked the same query, only 11% of cited domains overlap (ziptie.dev, 2026). This third-party finding validates why the AnswerGraph engine measures each engine independently.
11% domain overlap between ChatGPT and Perplexity for identical queries (ziptie.dev, 2026)
Cross-engine composite scores have no statistical validity
Third-party data (ziptie.dev) shows Perplexity's citation probability drops sharply with content age. Pages updated in the last 30 days have a 45 percentage-point advantage over pages older than 18 months.
45pp citation advantage for content under 30 days old (ziptie.dev)
Content older than 18 months is effectively invisible to Perplexity