1. The Cubic Rate Secret

For small heavy items, standard weight-based shipping is expensive.

Trick: Use PirateShip for "USPS Priority Mail Cubic" - charged by box size, not weight (up to 20lbs). Ship a 20lb item across the country for $9.

2. Weight Tiers

Under 1lb: USPS Ground Advantage

1-4lb: USPS Cubic (small box)

5lb+: UPS Ground usually beats USPS

3. Insurance Claims

Carriers deny 90% of claims citing "Insufficient Packaging."

Defense: Photo the item inside the box with bubble wrap visible before sealing. This photo wins every claim.

4. The Girth Rule

For large items: Length + (2×Width) + (2×Height). If this exceeds 130", shipping jumps from $40 to $150+.

Always measure before listing large items.