This is endlessly fascinating, thank you. I'm sure there's fun work being done by commodities traders using this type of data - sure enough there's a pricing section for API calls to their service. I would be curious to see how well it can predict performance for manufactured goods though - for large-scale consumers like Wal-Mart it might be possible to say that rising imports to the US (more container ships incoming) point to increased demand by consumers, therefore invest in Wal-Mart.