Two frameworks. Both keep the per-inbox rates Aydan set today ($4.50 under 500, $4.00 for 500 to 999, $3.50 at 1,000 and up). The difference is what decides which rate an agency gets. The calculator below lets you change every number and see totals and margin at real fleet sizes.
Change any figure. Totals recalculate for each fleet size. Margin uses the supplier cost you enter (Zapmail is $2 to $5 a box depending on age; the new supplier claims $1.80 Google).
| Fleet | A total | A margin | B best tier | B total | B margin | B vs A |
|---|
Margin is monthly revenue minus supplier cost times inboxes. Domains, tax and support are excluded. "B vs A" is what the agency pays more or less under B. Negative means B is cheaper for them.
One rule of thumb decides everything in Option B. The fleet size where a tier starts to pay for itself is:
break-even = (fee difference) ÷ (inbox price difference)
Growth at $199 with a $0.50 saving pays off at 398 inboxes. Scale at $499 pays off against Growth at 600 more. That is why the baseline numbers land close to Aydan's 500 and 1,000 thresholds. Move the fee or the step and the break-even moves with it.
Keep the inbox price close to the market and put the difference in the fee. Every agency will compare our $ per inbox against Zapmail and the $1.80 supplier. The fee is harder to compare and is where the platform value (engine, nightly report, decisions, receipts) gets paid for.
Do not make the steps between inbox prices too wide. A $1.00 step makes the top tier a must-buy for anyone over 500 inboxes and turns the middle tier into dead weight. Steps of $0.50 keep three live choices.
Starter at $0 or a small fee. $0 gets small agencies in with no friction and lets the free top-of-funnel report flow straight into a paid order. A $49 to $99 fee filters the ones who will never buy 50 inboxes. Either works; it is a sales decision, not a maths one.
Negotiate the fee, hold the unit price. A big agency asking for $3.25 gets "Scale with the fee waived for six months" instead. Same money for them, and the list price survives.
Aydan likes client workspaces as the primary limit. The rest are options. "In the dashboard now" means the field already exists in the prototype and enforcing it is small work; "backend" means Charles.
| Lever | Starter | Growth | Scale | Where it lives |
|---|---|---|---|---|
| Client workspaces | 3 | 15 | Unlimited | In the dashboard now (workspace switcher, Add workspace) |
| Team seats | 2 | 10 | Unlimited | In the dashboard now (Settings > Team) |
| API keys | 1 | 5 | Unlimited | In the dashboard now (Settings > API keys) |
| API rate limit bucket | Shared | Own bucket | Own bucket, higher | Backend. Matches the per-customer bucket we asked Zapmail for |
| Landing Factory pages | 10 | 100 | 250 (Pro zone plan) | In the dashboard now (Landing Factory slots) |
| Registrar connections | 1 | 3 | Unlimited | In the dashboard now (Settings > Registrars) |
| Nightly report cadence | Weekly | Nightly | Nightly plus on-demand | Backend scheduler |
| Bring-your-own inventory | View only | Managed in rotation | Managed in rotation | In the dashboard now (plan step 1 switch) |
| Decisions engine | Flags only | Flags and one-click actions | Auto-apply with rules | Dashboard plus backend |
| Placement tests | None | Monthly allowance | Weekly allowance | Backend (supplier feature) |
| Revision and receipt history | 30 days | 1 year | Unlimited | Backend storage |
| White-label dashboard domain | No | No | Yes | Backend and DNS |
| Support | Shared Slack channel | Slack plus an onboarding call | Ops |
Numbers in the tier columns are starting points to argue with, not proposals.