Pirate Ship offers great USPS discounts—up to 87% off—that help small sellers...

https://shipping-discounts.s3.amazonaws.com/goshippo/video/pirateship-shipping-reviews.html

Pirate Ship offers great USPS discounts—up to 87% off—that help small sellers save big on shipping. Its support is email-only, which works if you don’t need instant help. But if you want DHL Express or faster customer service, Shippo might be a better fit