Indicator detail
Concentration Index
Measures how concentrated listing activity is among repeat advertisers within a monthly snapshot.
Latest month
2026-09
Latest series value
29%
Coverage
12,236
Method
The published outputs include top-share measures and a Herfindahl-Hirschman style concentration score.
Interpretation caution
Concentration may reflect agencies, reposting strategies, or market structure, not ownership certainty.
Largest latest regions
Regional context
East London
Incall £100 | Intimacy 81%
1,315
North West London
Incall £100 | Intimacy 77%
536
North London
Incall £110 | Intimacy 86%
462
West London
Incall £100 | Intimacy 80%
419
Birmingham
Incall £120 | Intimacy 75%
394
South West London
Incall £120 | Intimacy 82%
365
Central London
Incall £130 | Intimacy 71%
278
Manchester
Incall £130 | Intimacy 76%
265