This is a tragedy of the commons argument. It's a nice sentiment, but Amazon doesn't need all that many merchants to sign up to get their data, so they will get

This is a tragedy of the commons argument. It's a nice sentiment, but Amazon doesn't need all that many merchants to sign up to get their data, so they will get the data on your shop, whether you sign up or not. If you sign up, it's a 1.25% pay rise for 18 months ... Yes eventually technology will eat your lunch, but that's coming independant of your signing up or no.