Paid services necessarily require a higher level of trust (since you are handing them money) than random internet services. So we are off-topic from ssh keys and identity.

If you don't want someone knowing your personal payment details (CC #, billing address), then pay in cash and use services don't deliver things to your home. And if you can't, then just don't use a service.

But that's living in way too much paranoia for most of us.