This calculator is not a forecast. It shows what birthday automation can be worth when your list is warm, consent is clean, the offer is credible, and follow-up happens every week without a manual export-clean-send cycle.
Treat this as a planning model: warm opted-in families, a relevant offer, and consistent follow-up make the play believable. If one of those is weak, move the sliders down.
Does it work? Use the party slider as a conservative revenue scenario. What does automation save? Use the manual-hours section for work your team no longer has to repeat. The real test is consistency: if the play would not happen every week by hand, automation is doing useful work before the first extra party is counted.