I wonder how they compare to existing services, like Veriship, which has pretty much the same messaging, and payment model? That is, how does MyKickback differentiate its self from existing audit services?
Yes. It's not cost effective if you can't scale with automation.
Why don't the shipping companies block such services from their API
UPS and Fedex depend on the guarantees. I believe the negative backlash to block companies enforcing those guarantees would cost more than the money they'd save.