eShoppers now savvy: Arbitrage across e-commerce outlets such as eBay and Amazon gone?

Check out the perfect tracking of the number of visitors to eBay and Amazon since mid 2005, showing the nonstationarities of shopping seasons. Whether this reflects that a majority of shoppers checks out both Amazon and eBay before buying, or whether the audiences have magically stabilized at equally large sets with little overlap, cannot be gleaned from these data. I would venture the former.