How does paribus work?

Sure, here's a simulated question based on the paragraph "How does Paribus work?": "Hey there, I've been hearing a lot about Paribus recently and I'm curious about how it works. Can you give me a brief overview of its functionality? I'm specifically interested in understanding how it helps consumers save money and how it connects with retailers. Is there a sign-up process or any fees involved? Also, how does Paribus ensure the security of my personal information? I'd appreciate any insights you can provide.