Costco's website goes down or becomes sluggish primarily because their infrastructure gets hammered during flash sales, holiday promotions, or when a viral deal hits social media. They're a retailer first, not a tech company, so their web stack isn't built with the same redundancy as Amazon or Shopify. When 200,000 people try to grab $20 off a TV simultaneously, their servers choke. Common causes include: - Browser cache conflicts with updated site code, especially after Costco pushes changes - CDN regional failures where Akamai or their content delivery network drops packets in certain provinces or states - Cookie or session token corruption if you've been logged in for weeks without clearing data - Mobile app sync issues when inventory APIs lag behind the web version If Costco's site won't load for you, clear your browser cache and cookies first. Try incognito mode or a different browser. Disable VPNs or ad blockers temporarily since Costco's checkout flow is sensitive to modified headers. On mobile, force-close the app and restart your phone. If the site still fails after 30 minutes, it's likely a server-side issue and you'll need to wait. From a design perspective, Costco prioritizes in-warehouse experience over digital polish. Their site still feels like 2012 because they're not incentivized to invest heavily in web performance when 70% of revenue comes from physical locations. Compare that to a digital-native brand where one second of latency costs millions. At Ottawa SEO, when we audit e-commerce clients, we stress-test checkout flows under simulated traffic and implement caching layers that Costco clearly skips to save cost. For a $240 billion company, their web reliability is surprisingly mediocre. If you're running an online store in Ottawa or Toronto, learn from their mistakes: use a robust CDN, load-balance across multiple servers, and monitor uptime with tools like Pingdom so you don't lose sales when traffic spikes.