The only company in the vertical that publishes its take rate — 42.8% on top of participant pay — and the best public anchor for what this spread actually is.
Prolific matters out of all proportion to its size for one reason: it is the only company in this entire vertical that publishes what it keeps.
From its own pricing page: "our platform fee is usually 42.8% for corporate customers, and a discounted 33.3% for academic or non-profit customers." Minimum participant pay is £6.00/$8.00 per hour; the recommended rate is £9.00/$12.00 (Prolific pricing).
#Why 42.8% is the number to remember
The fee is charged on top of participant rewards, not deducted from them. So a researcher paying £100 to participants pays £142.80, and participants receive 100/142.80 = ~70% of total spend — which is exactly how Sacra frames the same arrangement (Sacra). The two descriptions are arithmetically identical, and that consistency is the point: this is the one place in the market where the gross and net figures can be derived from each other without a leak.
Set it against everything else that is pinned down:
| Company | Take / gross margin | Basis |
|---|
| Prolific | 42.8% fee on top of pay (~30% of gross) | Published |
| Mercor | 27% (2025), 33% (Q2 2026) gross margin | Leaked to The Information |
| Handshake AI | 60–70% paid to contractors ⇒ ~30–40% take | Reported |
| micro1 | ~30–40% implied by $150–200M net on $500M gross | Reported, internally inconsistent |
| Appen | 40.3% gross margin | Audited |
| Innodata | 49% adjusted gross margin | Audited |
Prolific's disclosure brackets Mercor's leaked margin from above, and Appen and Innodata bracket it from the public side. The convergence of six independent figures on a 30–45% band is the strongest evidence in the atlas about what this vertical's spread actually is — and it is a services spread, not a software one. See What a rake can actually be and GMV is not revenue.
#What it sells now
Prolific began in 2014, founded by two Oxford PhD students, as a marketplace for academic research participants. CEO Phelim Bradley has pivoted it into AI evaluations, RLHF and red-teaming, which is where Sacra attributes the growth to ~$350M annualised as of April 2026 — a figure that, because Prolific books its platform fee rather than the participant rewards it sits on top of, is close to net and not comparable to the gross run-rates elsewhere in this vertical.
Not verified
That $350M is a Sacra estimate, not a company disclosure, and is tagged [WEAK] in the research notes. Prolific has never published a revenue figure.
If the estimate is even directionally right, Prolific is the highest revenue-per-dollar-raised business in the sector: ~$350M of revenue on ~$33.4M of total capital, roughly 10x. Compare Scale AI at ~$1.6B raised, or Mercor at ~$484M.
#Supply
200,000+ ID-verified active participants across 40+ countries, a 2M+ waitlist, 11,000+ AI annotation specialists and 5,000+ active AI taskers (Sacra).
Note "ID-verified." Prolific's original buyer — an academic running a behavioural experiment — cares about data integrity in a way a lab buying volume historically did not, and identity verification is baked into the product rather than bolted on. That matters more now than it did: academic work confirms that chatbot-assisted cheating contaminates crowdsourced behavioural research at scale (Asher et al., 2026). See Who is actually on the other end.
#The read
Prolific sits at the cheap end of the wage ladder — $8/hr minimum, $12/hr recommended, against Handshake AI's $100–125/hr average and Mercor's $81–100+/hr. It is not competing for the same supply as the expert-data names, and it is not winning nine-figure lab contracts.
What it demonstrates is the shape of the business stripped of the GMV headline. A ~30% share of gross, a fee that is visible on the pricing page, a fragmented buyer base of researchers and labs rather than two dominant customers, and no valuation mark to defend. On One customer is a binary event alone it is structurally safer than anything else in this vertical.
Gap in the record
Prolific's valuation, profitability, customer concentration and 2026 revenue are all undisclosed. The 42.8% fee is the only hard number the company itself has put on the record.
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