Venmo has no buyer protection. It may be safe to use them with Amazon but I tend to stay away form anything that has no protection. More info: https://venmo.com/legal/us-helpful-information/
It's always been a long time held precaution with many of us to NEVER leave your payment info on any such apps. They are just not a safe tech or protection when hackers can easily breach even bigger corps and have even smacked the government OPM years ago.
