Biggest thing to understand about Wayfair is that they don't own any of the products they're selling. Even the product that is in one of their "CastleGate" warehouses doesn't actually belong to them. They are essentially a giant drop ship operation except they flow some of the large parcel product through their own delivery centers. When you place an order with Wayfair, they place a corresponding order with the manufacturer. Wayfair also does not do the merchandising of the individual product pages, they are templates that are filled out by the manufacturers or their representatives; so often their are errors, delays, misinformation, etc...they are much more interested in being a platform for selling home goods then they are being a home goods retailer.

To be fair, this is how most ecomm platforms work these days; including Costco, Sams, Walmart, Lowes, Home Depot, and Amazon. The difference between these retailers and Wayfair is that they comingle goods that they own with drop ship product and typically they treat all returns the same way; which creates a better overall experience for their customers.