# Visitor identification by money raised at Y Combinator companies (v1.0)

Dedicated visitor-identification vendors found on the homepages of 5,386 Y
Combinator companies, cut by money raised, last round, hiring, traffic and YC
status. Data behind the Installmap report "YC's best-funded startups are 3x as
likely to de-anonymize you".

Data: rendered homepage crawl fetched on 2026-09-04 and scored on 2026-09-27
against 30 vendor fingerprints (7 of them name level), joined by domain to
Crunchbase (funding total, last round and its date, Semrush visit estimates;
the latest round date in the snapshot is 2026-09-18) and to the YC company
directory (hiring flag, top-company flag, status; records from 2026-08-25).
The 58 named companies were rendered again on 2026-09-27.

## Files

| File | One row per | Columns |
| --- | --- | --- |
| `domains.csv` | scored YC homepage (5,386) | domain, company, batch, batch_year, industry, yc_status, team_size, hiring, yc_top_company, crunchbase_match, funding_band, last_round, last_round_type, last_raise_date, semrush_visits, semrush_mom_pct, visits_band, traffic_change_band, any_vendor, name_level, company_level, vendors |
| `by_funding.csv` | Crunchbase funding band | n, any vendor, name level (counts, percentages, 95% Wilson intervals) |
| `by_funding_b2b.csv` | funding band, YC industry B2B only | as above |
| `by_round.csv` | last round | as above |
| `by_hiring.csv` | YC hiring flag | as above |
| `by_status.csv` | YC status | as above |
| `by_visits.csv` | Semrush monthly visits band | as above |
| `by_visits_b2b.csv` | Semrush monthly visits band, YC industry B2B only | as above |
| `by_traffic_change.csv` | month-on-month change in Semrush visits, sites with 1,000 or more visits | as above |
| `same_size.csv` | team size and last round, active YC B2B companies from the 2019-2022 batches | as above |
| `regression.csv` | model, outcome and term | odds ratio with 95% Wald interval |
| `vendors_best_funded.csv` | vendor on the 195 homepages of companies with $100M or more raised | level, domains, share |
| `best_funded_taggers.csv` | named company (58) | raised in $M (Crunchbase), last round, vendors on each fetch, vendors on both, level, recheck |

Percentage columns hold percentages (27.2 means 27.2%). Counts of one to four
print as `<5` in `vendors_best_funded.csv`. `any_vendor`, `name_level`,
`company_level`, `hiring`, `yc_top_company` and `crunchbase_match` are 1 or 0.
`semrush_mom_pct` is the month-on-month change in percent; `traffic_change_band` is set for homepages with 1,000 or more monthly visits and a known change.

## Cite

Installmap Research, "YC's best-funded startups are 3x as likely to de-anonymize you", installmap.com, 2026-09-27, https://installmap.com/research/yc-best-funded-visitor-identification

Licensed CC BY 4.0. Source: Installmap. Funding fields come from Crunchbase and
visit estimates from Semrush, as carried in Crunchbase records.