Clay and AI prospecting: what data enrichment is, how it works and its legal limits

Clay is a data tool for sales and growth teams. It works like a spreadsheet where each row is a company or contact and each column is a query: to a data provider, a website or an AI model. The result is an enriched list (industry, size, tech stack, recent news) and a personalized message per row. It has given its name to a new professional profile: the GTM engineer.

What waterfall enrichment is

No data provider has every email or phone number. The waterfall method queries several providers in order: if the first doesn't find the data, it moves to the second, and so on. You only pay for data found, and coverage rises compared with a single provider.

Which tasks it solves

• Building account lists from precise criteria (industry, size, technology, recent hiring).
• Finding the right person at each account and their business contact data.
• Researching each account with AI: reading its site, summarizing its offer, spotting buying signals.
• Writing the opening line or full personalized message for each contact.
• Pushing data to the CRM or sequencing tool.

A typical step-by-step flow

1. Define your ideal customer profile from your best customers' data.
2. Import or find matching accounts in Clay.
3. Waterfall-enrich and drop accounts that don't fit.
4. Use an AI step to research and draft the message.
5. Manually review a sample before sending.
6. Measure replies and adjust criteria and messages.

The drafting step improves a lot with a good prompt; the structure is the same we explain in prompts for copy. And this flow is the clearest example of AI agents applied to marketing.

Legal limits in Europe

In the EU, prospecting with personal data (including a person's work email) is subject to GDPR. You need a legal basis, usually legitimate interest with a documented assessment; to inform the recipient where their data came from; and to make objecting easy. In Spain, the LSSI also restricts commercial emails without prior consent, with exceptions for existing customer relationships. Review each case with legal advice.