{
  "measured_by": "GetIntel",
  "measured_on": "2026-08-10",
  "window": {
    "start": "2026-07-10",
    "end": "2026-08-10",
    "distinct_run_days": 20
  },
  "method": "The brand's FULL tracked prompt set across the window: 130 prompts, each run repeatedly against 4 engines, giving 520 prompt-engine series. 60 of those prompts are currently live; the other 70 were archived on 3 August 2026 when an unrelated profile edit re-minted the set. Archived prompts are included because each prompt-engine series is measured independently and churn does not depend on whether the prompt was later retired. For each series, consecutive runs were compared on the SET OF CITED DOMAINS and on whether our own brand was cited.",
  "scope": {
    "prompts": 130,
    "live_prompts": 60,
    "archived_prompts": 70,
    "engines": 4,
    "prompt_engine_series": 520,
    "total_probe_runs": 4880,
    "consecutive_run_pairs_compared": 4220
  },
  "interval_between_consecutive_runs_hours": {
    "p10": 10.9,
    "p25": 23.8,
    "median": 24.0,
    "p75": 24.1,
    "p90": 24.1,
    "mean": 37.2,
    "note": "73.4% of gaps fall in the 20-30h band, so 'daily' describes the median case and not every case."
  },
  "source_churn": {
    "pairs_where_cited_source_set_changed": 3901,
    "pct": 92.4,
    "mean_jaccard_overlap_between_consecutive_runs": 0.236,
    "by_engine": [
      {
        "engine": "openai_chatgpt",
        "pairs": 1050,
        "changed": 1047,
        "pct": 99.7
      },
      {
        "engine": "gemini_direct",
        "pairs": 1058,
        "changed": 1047,
        "pct": 99.0
      },
      {
        "engine": "google_ai_overviews",
        "pairs": 1039,
        "changed": 987,
        "pct": 95.0
      },
      {
        "engine": "perplexity",
        "pairs": 1073,
        "changed": 820,
        "pct": 76.4
      }
    ],
    "mean_jaccard_by_engine": {
      "note": "The pooled 0.236 is an average ACROSS FOUR ENGINES and must never be quoted as a ChatGPT figure. Perplexity's 0.514 pulls the pooled number up; ChatGPT's own overlap is 0.167.",
      "perplexity": 0.514,
      "google_ai_overviews": 0.169,
      "openai_chatgpt": 0.167,
      "gemini_direct": 0.101,
      "pairs": {
        "perplexity": 1133,
        "gemini_direct": 1116,
        "openai_chatgpt": 1110,
        "google_ai_overviews": 1078
      },
      "why_pair_counts_differ": "These per-engine Jaccard figures rest on 4,437 pairs (1133+1078+1110+1116) while the binary did-the-source-set-change figures above rest on 4,220 (1050+1058+1039+1073). They are two separate pulls with slightly different filters: the churn pull required at least one side of a pair to be non-empty, the Jaccard pull was run later over all consecutive pairs. Quote each rate with ITS OWN denominator: 99.7% belongs to 1,050 ChatGPT pairs, 16.7% belongs to 1,110."
    }
  },
  "brand_presence_stability": {
    "per_consecutive_run_pair": {
      "pairs_compared": 4220,
      "pairs_where_our_mention_flipped": 169,
      "pct_of_pairs": 4.0
    },
    "per_prompt_engine_series": {
      "series_compared": 520,
      "series_that_flipped_at_least_once": 65,
      "pct_of_series": 12.5,
      "series_that_never_changed_state": 455
    },
    "single_check_reliability": {
      "applies_to": "ONLY the 65 series observed in both states, not all 520",
      "pct_of_single_checks_landing_on_the_minority_state": 23.2
    },
    "by_engine": {
      "denominator_note": "These use ALL 4,360 consecutive run pairs (130 series x 4 engines). The source-churn figures above use 4,220 because a churn comparison requires at least one of the two runs to have returned citations at all.",
      "engines": [
        {
          "engine": "openai_chatgpt",
          "pairs": 1090,
          "flips": 84,
          "flip_pct": 7.7,
          "series": 130,
          "series_that_flipped": 31,
          "we_were_cited_in_pct_of_runs": 7.2
        },
        {
          "engine": "perplexity",
          "pairs": 1090,
          "flips": 46,
          "flip_pct": 4.2,
          "series": 130,
          "series_that_flipped": 17,
          "we_were_cited_in_pct_of_runs": 8.5
        },
        {
          "engine": "google_ai_overviews",
          "pairs": 1090,
          "flips": 37,
          "flip_pct": 3.4,
          "series": 130,
          "series_that_flipped": 16,
          "we_were_cited_in_pct_of_runs": 2.9
        },
        {
          "engine": "gemini_direct",
          "pairs": 1090,
          "flips": 2,
          "flip_pct": 0.2,
          "series": 130,
          "series_that_flipped": 1,
          "we_were_cited_in_pct_of_runs": 0.1
        }
      ],
      "total_flips": 169,
      "total_pairs": 4360,
      "overall_flip_pct": 3.9
    },
    "perplexity_unstable_series_detail": {
      "flipped_series": 17,
      "absent_more_often_than_present": 11,
      "present_more_often": 6,
      "tied": 0
    }
  }
}