The prospect of sending in a redemption card that is worth anywhere between $75-$300 is a scary thing. The auto PW are a good $200 of value and from HP a Ron auto redemption card would be a good $200-$300 redemption. The big question is how do you minimize the risk, lets say you had 2 Kate auto PW and 2 Kate reg Auto's you would have to insure them for as much as $600 to cover the value. That is a lot of money added up.
I sure wish nonsport manufacturers would consider online redemption cards like Upper Deck does for there sports cards (maybe they have). I will try to scan one of my UD sports card redemption cards tonight and post an example. It is sure nice to do it online I have a redemption card for a Dan Marino Auto'd Jersey (not card, but real jersey) worth retail of $600 it was nice to be able to redeem it online instead of having to send it in insured for full value saved me a lot of money and worry.
I agree online redemptions seem to be the next step in the progression of technology and the hobby.
One problem you would have with redemption cards is proving their worth to the Post Office if they did get lost. I've fought with them over autograph cards and such before and the only luck I've had is producing the invoice to the customer as proof of value. Luckily, not many packages get lost in reality.
One also might say that claiming a high value makes it more likely for a package to go missing because it automatically lets postal workers know it's worth something.

Ed