Pulsar · Field guide · No. 20 · The warm crowd you already paid for, audiences that auto-refill, and the single cheapest optimization in advertising.
The Faucet, Not the Bucket
The cheapest customer is the one who almost bought. Build warm audiences that refill themselves, work them hottest-first, and stop paying to re-sell to people who already bought.
The crowd you already paid for
Every expensive step — attention, interest, desire — is already bought and paid for on the people who almost converted. On one real store’s 30-day pixel: 83 added to cart and left, 27 reached checkout and stopped, against just 10 buyers.
The cart abandoners alone were 8× the customer count — warm, identified, and cheaper to convert than any cold stranger.
A faucet, not a bucket
Export a list once and it goes stale the next day — you end up chasing people who already bought. A retargeting audience should be dynamic: auto-add on stall, auto-remove on purchase.
Bucket (static)
exported once
Fixed list. Decays immediately, includes people who’ve since bought, wastes spend re-selling.
Faucet (dynamic)
rule-based
Membership updates itself — in on stall, out on purchase. Always current, never re-sells a buyer.
Work the tiers hottest-first
Not all warm is equal. Spend on the hottest, most recent intent first — and give hotter tiers shorter windows.
| Tier | Intent | Window |
|---|---|---|
| 1 · Checkout started | hottest | short — 3–7 days |
| 2 · Added to cart | hot | 7–14 days |
| 3 · Viewed a product | warm | 14–30 days |
| 4 · Visited the site | cool | 30–60 days |
Exclude your buyers — the cheapest optimization there is
The single cheapest optimization in advertising: stop paying to reach people who already bought. Pure saved spend — no creative to test, no learning phase, zero risk.
Match the message to the reason
The blanket discount is the laziest nudge — it pays people who’d have bought anyway and teaches your hottest audience that abandoning earns a coupon. Match the message to why they stalled.
| They stalled because… | Say… |
|---|---|
| shipping shock | a shipping answer (free threshold, speed, cost upfront) |
| trust worry | guarantees, returns, reviews |
| just distracted | a simple reminder — no discount needed |