Forgive me if this was already discussed, but the address pictured had no value at the time of the original post...now it contains 1 bitcoin...are you loading them as you fill orders? Are the private addresses really destroyed (save the copy in the coin)?
Yes and yes. I load each coin once I have confirmed that I haven't rejected it for some reason (such as ruining the label while peeling it - which happens a fair bit - and there's only one for each address). Of course, only the public addresses are needed for this process. I have a little app that helps me load them in large batches using the bitcoind "sendmany" RPC command.
The private keys were generated on a fresh OS install dedicated just for the purpose, on a computer that never connected to any networks, and the entire batch printed on sheets of paper directly from that machine. I have since securely erased the hard drive.
Loading them after arrival confirmed by customer also means you can be sure the value isn't lost if the coin is lost/stolen. Which means you could use lower cost shipping like air mail.
On the other hand there's no reason why the customer couldn't load the value after arrival and just pay you for a blank coin (has address+key), removing that whole process from your workload.
Either way, only by looking in the block chain do you know what value the coin actually holds.