TL;DR: 1st-party is your own data. 2nd-party is partner / network data. Zero-party is what people tell you directly. Unstuck Engine handles all three through the same signals table, but each category has its own setup pattern.
1st-party
Signals from systems you already own. The data is yours; no third party intermediates.
Examples | Source
Replies to your outbound | Smartlead, Apollo, HubSpot Sequences, Salesloft
Demo views | Vidyard, Loom, Wistia, Mux
Form fills | HubSpot, Marketo, your custom forms
Page views (high-intent pages) | PostHog, Segment, your analytics pixel
CRM stage changes | HubSpot, Salesforce
Custom events | Webhook
Setup: connect the source via OAuth or webhook, pick which events become signals. 1st-party signals are the highest-converting category in most workspaces — the prospect already raised their hand somewhere.
2nd-party
Signals from partner and network sources — data the prospect produced in public or in a partner system Unstuck Engine has access to.
Examples | Source
LinkedIn keyword posts | LinkedIn (via Apify actors)
Job changes | LinkedIn
Hiring signals | LinkedIn jobs, GitHub jobs
Funding events | Crunchbase, PitchBook (when connected)
Tech-stack changes | Wappalyzer, BuiltWith
News mentions | Google News, custom RSS
Setup: most 2nd-party sources are pre-wired; you just enable the signal and (in some cases) pick the LinkedIn account that authenticates the scraping. Privacy posture: only public information is captured — public LinkedIn posts, public job listings, public funding announcements.
Zero-party
Signals from self-declaration — the prospect actively told you something.
Examples | Source
Calendar bookings | Calendly, Chili Piper, HubSpot Meetings
Demo requests | Your demo-request form
Survey responses | Typeform, Tally
Product signups | Your auth provider, Stripe customer events
Self-reported persona | Custom form fields
Setup: connect the source as a webhook OR upload via the Records API. Zero-party signals carry the highest conversion intent but the lowest volume.
Why the distinction matters
Three reasons:
- Source credentials live per category. 1st-party signals need OAuth into your tools; 2nd-party signals use Unstuck Engine's own partner credentials; zero-party signals usually arrive via webhook.
- Privacy posture differs. 1st-party is yours; you decide what to do with it. 2nd-party is public data; we capture only what's publicly available. Zero-party is opt-in by definition.
- Conversion rates differ. Zero-party > 1st-party > 2nd-party, typically. The Insights page breaks reply rate, meeting rate, and signup rate by signal source so you can see the gap.
Mixing categories
The most effective audiences blend all three. A canonical "hot audience" might require:
- A 2nd-party signal (LinkedIn post mentioning your category in the last 7 days) and
- A 1st-party signal (visited a high-intent page on your site) or
- A zero-party signal (replied to a sequence)
Build that audience inside the Audience Builder; Copilot can draft it from one sentence: > show me leads with any signal in the last 7 days from any source, ranked by engagement score.