Comment by bastawhiz

I agree, even if you say that my browser is a user agent using Amazon that's also a user agent, it's a real stretch to say that it's giving me any control at all.

My browser speaks TLS and HTTP for me. Maybe it talks if I'm low vision. Maybe it adjusts the page to be more visually appealing. What is Amazon doing? They're using the same interface that I am. They're completing an identical transaction to me. I'm maybe sure I could sit down with a sufficiently large piece of paper and a sufficiently advanced calculator and crunch the numbers to speak TLS (for a packet or two, at least). Not enough to complete a transaction, though.

But I can confidently place an online order. There's no control that Amazon can offer. In fact, they're essentially just giving me a rebranded interface to perform the same action I can perform on another page.

Just because it's a service doesn't make it a user agent.