# Method

## Sources
- Apple Podcasts "Top Shows" top-100 for 18 storefronts (us, gb, ca, au, de,
  fr, es, it, nl, se, br, mx, jp, in, ie, nz, pl, kr), fetched 2026-09-06,
  HTTP 200 and 100 results for every storefront. 18 files, 1,800 slots.
- Podcast Index feed dump dated 2026-08-16, through the join already committed
  in data/lists/charts.json. It supplies host and category1 only. No count in
  this report has the dump in its denominator.

## The unit
A slot is one of the 100 ranks in one storefront. A show that charts in six
storefronts holds six slots. Slots are not downloads, listeners or revenue, and
Apple does not publish what the ranking measures.

## The join
The 1,800 slots hold 1,479 distinct itunesIds. 1,703 slots
(1,387 distinct ids) match a dump row on itunesId. The other
97 slots carry a blank host and category1. Every parent, slot and
storefront count in this report is computed over all 1,800 slots and does not
depend on the join.

## The parent map
artistName is Apple's publisher string, written by the publisher. Strings are
rolled up to a parent company by hand in data/chart_publisher_parents.csv.
The map covers every string holding 2 or more slots plus every string naming
one of the companies the report discusses. A row that merges a string into a
larger owner carries an evidence_url: a Wikipedia article or the company's own
page showing the ownership. 111 rows have an empty evidence_url. 109 of them
keep themselves as their parent. The other two are co-production strings whose
slots went to the first producer named in the string, "Historiska Media | Acast"
to Historiska Media and "Simone Pieranni - Chora Media" to Chora Media, and no
published number depends on either.

## The co-production rule
A string naming more than one producer ("iHeartPodcasts and Glass Podcasts",
"The HISTORY Channel | Back Pocket Studios | Audacy") carries
co_production = 1 and its slots go to the first named company, or to the first
named company where the string opens with a person's name. A company named
second or third in a string therefore gets no slot from it. This is the reading
the tables use. The report also gives the looser count, every slot whose string
names a company anywhere, for the companies it discusses, and the two readings
differ: iHeartMedia holds 19 slots as first-named and is named anywhere in 24.

## Rounding and small cells
Counts are exact. In the report tables, a slot count between 1 and 4 prints
"<5": the Slots, US slots and UK slots columns. Show counts and storefront
counts print exact, because neither says how many chart slots a company holds.
The CSVs carry every raw count. No share is published on a base under 100.

## Caveats
- artistName is self-declared. A show produced or distributed by one company
  but published under its own studio name counts to the studio.
- Distribution and sales deals are invisible here. A network that sells the ads
  for a show without appearing in its publisher string holds no slot in these
  tables.
- The charts were fetched on one day, 2026-09-06. Nothing here is a trend,
  and a chart on another day gives other slots.
- A storefront is Apple's store, not a country of origin. A US show charting in
  Ireland counts in the ie row.
- Slots are not audience. A company with few slots may have more listeners than
  a company with many.
- The parent map is a judgement over public ownership records, and 111
  of the 242 mapped strings stayed under their own name because no public
  record was found. Those strings are counted, never merged.
- The dump is dated 2026-08-16 and the charts 2026-09-06, three weeks
  apart, so a show that entered the index after the dump cannot join.

Data: CC BY 4.0, Podcastquery, September 2026