$ man clay-wiki/contact-sourcing

Contact sourcing is where your pipeline starts. Bad sourcing = bad pipeline, no matter how good your enrichment is. The hierarchy: your own CRM data first (always), then LinkedIn Sales Navigator for targeted account-level search, then Apollo or ZoomInfo for bulk firmographic-filtered exports, then industry databases for niche verticals, then Apify for scraping when standard sources don't cover your market. Every source has strengths and blind spots. Cross-reference at least two for any list over 1,000 accounts.

PATTERN

Apollo: best for bulk export with firmographic filters. Strong US tech coverage. Weaker on European and SMB markets. Good for building initial contact lists that you'll enrich further in Clay. Clay native sourcing: use Clay's built-in people search when you need to source contacts at specific companies already in your account table. It's context-aware — you give it a domain, it finds people. Direct APIs (via HTTP column): use when you need data that no built-in integration provides. LeadMagic for European email coverage, Prospeo for validation, custom endpoints for niche databases. The rule: start with the cheapest option that gives you acceptable coverage. Apollo's bulk export is often free or low-cost. Clay native sourcing uses credits. APIs have their own pricing. Layer them based on what the cheaper option misses.

PATTERN

Never start by sourcing contacts. Start by identifying accounts. Build your account table first — qualified companies that fit ICP. Then source contacts at those companies. This prevents you from importing 5,000 contacts at companies you'll never sell to. The flow: Define ICP → Source companies → Qualify companies → Source contacts at qualified companies → Qualify contacts by persona → Route to outreach. Every step narrows the funnel. You might start with 10,000 potential companies, qualify 2,000, and source 4-6 contacts per company. That's 8,000-12,000 contacts, all at companies you've already confirmed fit ICP. That's a clean pipeline.

PRO TIP

When Apollo and LinkedIn don't cover your market, Apify is the answer. Job scraping from Indeed tells you which companies are hiring for specific roles — if they're hiring SDRs, they have an outbound motion. Instagram scraping surfaces SMBs that don't appear in enterprise databases. Yelp scraping maps local businesses by category, review count, and location. Apify isn't a default tool. It's the tool you reach for when standard sources return thin results. For franchise TAMs, restaurant groups, local service businesses — Apify is often the only way to build a complete universe.

PATTERN

Every provider has blind spots. Apollo misses certain industries. LinkedIn has company-size minimums. ZoomInfo skews enterprise. The fix: cross-reference at least two sources for any TAM over 1,000 accounts. Import from source A. Import from source B. Deduplicate by domain. Compare coverage — which companies appear in both? Which only appear in one? The ones that appear in both are high-confidence. The ones in only one source need validation. Cross-referencing also catches data quality issues. If Apollo says a company has 500 employees and ZoomInfo says 50, something is wrong. Investigate before you enrich.

ANTI-PATTERN

Sourcing contacts before qualifying accounts. You end up with thousands of contacts at companies that don't fit ICP, wasting enrichment credits and campaign slots on people who will never buy. Another mistake: trusting a single source. Every database has stale records, missing companies, and wrong data. If your entire TAM comes from one Apollo export, you're building on a shaky foundation. Cross-reference. Relying on Clay's sourcing for everything. Clay is excellent at enrichment, but it's not a sourcing database. Use Apollo, LinkedIn, and industry databases to source. Use Clay to enrich. Different tools for different jobs.