"I was accepted, but then it said the study is full"
This is one of the most common things participants ask about — especially on instant studies (AI interviews and short tasks). It's not a glitch; here's what's happening.
Why this happens
Spots are allocated first-come, first-served:
Instant studies fill in real time, and more people are invited than there are final places, to fill quotas quickly.
Being accepted confirms you matched the criteria — but for instant studies it isn't a reserved seat. Your place is only secured once you start and a spot is still open.
If the spots fill before you start, you're moved to the waitlist.
So you can be genuinely eligible and still find it full — others just got there first this time.
What the waitlist means
You're not yet confirmed, but there's still a chance: if someone who confirmed can't attend, we may select you from the waitlist. We'll be in touch if a spot opens and ask you to confirm — keep an eye out.
How to improve your chances next time
Act fast when an instant study opens — accept quickly to secure your spot.
Keep notifications on (Profile → Notifications) so you catch new and reopened opportunities.
Complete your profile — complete profiles are up to 4x more likely to be selected: How to Boost your Profile.
Waitlisted vs ineligible
Waitlisted = you matched, but there was no spot right now.
Ineligible = you didn't match the criteria — see Why am I ineligible.
See also I am on the waitlist, what does this mean?. Questions about a specific opportunity? Contact Help & support with the study name.