How can I detect which customer has made a payment using only one receiving address?
Can I embed a unique special message in the QR code (like a nonce) which I'll match against my database? Does it make any sense or is it too problematic (bitcoin client not embedding the message, unable to read the transaction message from the blockchain, etc..etc..)
If that's not an option, does it make any sense to embed a unique code on the least significant satoshis? (let's say the last 3 satoshis if I expect on average less than 1000 transactions occurring at the same time)