Residential proxies route each request through real consumer lines, preserving the “organic shopper” signature that eBay’s anti-bot filters expect, while automatic rotation refreshes the IP before rate counters trip. Sticky ports can pin a single address for 5-30 minutes—long enough to maintain a cookie session and add items to carts without losing context. Leading providers also expose high concurrency so bots crawl thousands of listings and order APIs in parallel without hitting per-route quotas.