Warm-intro hierarchy — 8 levels from cold inbound to family-equivalent referral; closest tie ≠ best referrer unless it carries domain-competent trust

Claim (synthesis of [[marsden-campbell-1984-closeness-best-tie-strength]] + [[levin-cross-2004-trust-mediates-tie-strength]] + in-domain practitioner record): Operational hierarchy of warm-intro quality for Ontario trades vendor selection, weakest to strongest:

1. Cold inbound (form fill, blind email, ad click) — no tie, no trust
2. Cold outbound from the vendor — negative trust prior; buyer must overcome assumption of low competence/benevolence
3. LinkedIn second-degree connection — marginal weak tie; useful for attention, not trust
4. HBA / trade-show acquaintance — weak tie (Granovetter); bridges clusters but does not transmit benevolence-trust. Useful for novel info, not the buying decision itself
5. Supplier-rep or subcontractor introduction — weak tie with structural brokerage (Burt); moderate conversion contingent on rep's competence-trust with the GC
6. Peer-coaching cohort member's introduction — medium tie with high benevolence-trust (cohort has shared financial detail); structural guarantee against misrouting because referrer's cohort reputation is at stake
7. Close professional ally (a GC the buyer has worked alongside for years) — strong tie with both competence- and benevolence-trust; highest conversion + strongest expectation-set
8. Family-or-equivalent reference — strong tie that may not carry competence-trust about marketing specifically but carries maximal benevolence-trust. Risk: expectation-set may be unrealistic because the referrer cannot adequately specify what they're recommending

The non-obvious finding: the closest tie is not always the best referrer. The closest tie that carries domain-competent trust is. A GC's brother who doesn't understand websites is a worse referrer than a peer-coaching cohort member who does.

Confidence: Applied inference, theory-consistent; not in-domain empirically measured.