GTM BUILD #2: The Market & The LIST

We aimed for 8,000 email sends a month, then found the market held 1 month of leads. Here’s part 2: the list, from market count to send-ready file, with every prompt, and the skill that runs it all.

In part 1 of this GTM build report, we built the foundation: email infrastructure: 14 domains, 50 mailboxes, warmed up and ready to send.

Here are the maths that turned into the biggest lesson of the whole project.

It wasn’t deliverability, and it wasn’t the copy.

It was the list. The first market we counted held only one month of leads.

• The fix took a few weeks, since the ICP had room to widen.

• The lesson took longer to sink in: run the maths before you size anything.

This is part 2 of the build. A new part at each phase, with the numbers, good or bad.

🗺️ The build in 7 phases

• Phase 1: EMAIL INFRASTRUCTURE

• Phase 2: THE MARKET AND THE LIST

• Phase 3: THE SIGNAL

• Phase 4: THE COPY AND THE PAGES

• Phase 5: LAUNCH AND FIRST SIGNALS

• Phase 6: RUN AND FIX

• Phase 7: RESULTS AND THE VERDICT

This part covers phase 2.

🏢 Quick recap: the client

A remote ecommerce marketing agency, around 60 people, selling retention services to Shopify brands.

Cold email had been switched off for a year, after 2 expensive tries that didn’t work.

The founder’s brief: “I just want to avoid very expensive tests.”

One line of maths

The agency committed to 8,000 emails a month. Each lead gets 3 emails. So:

8,000 ÷ 3 = about 2,667 new leads, every month

Then we counted the market: US Shopify brands with Klaviyo, in beauty and health, inside the agency’s revenue band and under 100 employees.

2,678 brands. In total.

The volume promise needed about as many new leads every month as the whole market held. One month of leads.

In September, the mailboxes ran at about 5% of the capacity they could send.

The spare capacity was fine. Domains burn in outbound, so spares always earn their keep.

And the fix was quick: we widened the ICP, which was too narrow. New categories, second contacts, a wider net. Step 7 shows all four moves.

The lesson is the order. Run the maths first, and you size the whole system to the market, instead of discovering the market after the promise.

🧰 Tech stack for this phase

• Company data: Store Leads

• Email finding: LeadMagic first, FullEnrich on the misses, Smartlead’s Smart Prospect as a last try

• Email validation: LeadMagic and FullEnrich on their own results, MillionVerifier (built-in on Smart Prospect’s)

• Dedupe: Smartlead’s global block list

• Claude Code: connected to Store Leads and the email tools, running one skill from domain list to send-ready file

📍 Phase 2: The market and the list

Seven steps, from “how many leads do we need?” to a list that’s ready to send:

1. Count your market against your volume

2. Set the list gate in Store Leads

3. Pick one persona rule

4. Check every domain before you pay for data

5. Find the emails, then validate every one

6. Dedupe against everything live in Smartlead

7. When the market runs dry: 4 ways to find more

Below: every step in full, with what we did, what I’d do differently, and the prompts.

Inside:

• The market-count prompt that tells you how many months of leads you have

• The exact Store Leads filters we used

• The homepage check that cut wrong brands from 69 to 22

• The validation rules that kept bounces under half a percent

• One batch, from 1,500 domains to 842 loaded leads

• Download: the enrich-list skill for Claude Code

Phase 2, step by step

Step 1: Count your market against your volume

Do this before you promise a volume, and before you buy a single mailbox. Start at the money and walk back:

1. Extra revenue target ÷ average deal size = deals needed

2. Deals ÷ your close rate = sales opportunities

3. Opportunities ÷ your opp rate per meeting = meetings

4. Meetings ÷ your meeting rate per lead = leads to enrol per month

5. Leads × 3 emails each = emails per month, which sets your mailboxes and domains

Then count your market, and check it holds enough leads for that monthly number, for at least six months.

Run it in Claude Code, with your data source connected:

Size my cold email system backwards from revenue. Ask me
one question at a time:
- extra revenue I want from cold email in 12 months
- my average deal size and close rate from meetings
- my meeting rate per lead, if I know it (else use 1-2%)

Then work out, with the maths shown:
1. Deals, meetings and leads to enrol per month
2. Emails per month (3 per lead), and the mailboxes and
   domains that needs (30 emails per mailbox per day)
3. Using [your data source], count the companies matching
   my ICP: [industry], [size or revenue], [location],
   [required tech]. Assume 60% yield a verified
   decision-maker.
4. How many months of leads that is at my monthly number.

If it's under 6 months, tell me which filter to widen
first, and what that does to fit. If my revenue target
needs more leads than the market holds, say so plainly.

Under six months of leads? Widen the ICP now, in order of least fit lost.

We did it in week three instead of week zero, and the system ran at 5% of capacity while the new segments spun up.

More on building a list from scratch: Build Your List With Claude Code.

Build Your List With CLAUDE CODE In Under an Hour.

Step 2: Set the list gate in Store Leads

The filters we used: