Setting up member-tier and birthday offers

First create tiers under Settings → Member Tiers (e.g. Gold), then target the promotion at that tier. For birthday offers, set the condition to “birthday month”.

• The member must be selected at checkout for the offer to trigger — eligibility is judged against the currently selected member.
• Birthday eligibility reads the member's birthday month, so fill in the birthday field; members without one are never treated as birthday customers.
• Auto tier upgrades are judged when checkout completes; if the order is voided, an upgrade it triggered is rolled back automatically.