eBay

eBay still carries the bones of an auction house grafted onto a fixed-price store. A listing may show a countdown timer and bid history, or a flat Buy It Now button, and the page has to make that mode legible at a glance — it doesn't always succeed. The auction countdown is its most distinctive interaction: a live clock that turns shopping into a deadline, with last-second sniping a known behavior the UI never really designed for. Seller feedback scores and percentage ratings are the original online trust system and remain central. The faceted left rail is powerful but dense, and condition (new, used, refurbished, for parts) becomes a critical filter the catalog can't fully standardize. Watchlists track items in the background until the clock runs down.