The U.S. Senate recently passed a bill that would allow states to collect sales tax on online purchases, potentially leveling the playing field between brick-and-mortar and online retailers. This may shift some purchases back to brick-and-mortar retailers, but it won't entirely change the trend of sales moving online. Fool editor Lauren Kuczala sat down with contributor Travis Hoium to see who the winners would be and why Amazon (AMZN -0.56%) may benefit despite having to pay more in taxes on its purchases.