Same thing here. Just now called my cell phone. Two rings and then hung up. No name on the caller ID. My privacy app says the call came from East Greenwich, Rhode Island.
I called back and a pre-recorded message said. "hi, this is jennifer with rewards redemption, you recently visited one of our affiliated sites. If you'd like a $100 award, please press 1. If you would like to be placed on our do not call list, press 2."