What does "as-is" mean, and why do I agree to it every time?

Second-hand, sold as it is. No warranty, no returns, and nothing behind it if the thing turns out to be a dud.

You'll tick a box saying you understand that — every time you buy, and every time you bid. Not once at signup. Every time, never pre-ticked. We store the exact words you agreed to alongside the tick, because "you agreed to our terms" is worth nothing if nobody can produce the terms.

That doesn't mean anything goes. A listing has to actually describe what it's selling. Scuffs the seller mentioned are your problem. A laptop that turns out to be a different laptop is ours, and that's what Report a problem is for.

One thing that catches people out: on auctions we ask at the bid, not at the win. You bid on Tuesday, and Thursday afternoon your card gets charged while you're at work thinking about something else. The bid is the moment you actually decided, so that's where the question goes.