Ok I dont know why people love Amazon more than play delivery and service seems to be about the same but what every it is the difference is negligible.
So when Amazon drop their price to match a competitor why buy from them? Its really counter-intuitive for people looking for a deal waiting for a particular site to sell it for the the SAME amount. In these cases Amazon is reacting rather than being proactive and they do it alot thus if there were no competitors around would they every drop their prices? So if this continues might Play not think "Why drop our prices Amazon will match and everyone buys it from them instead, when we have decided to take a hit and they are only reacting".
And thus competitors will drop their prices less. Obviously if Amazon is cheaper buy it from then but if they have just matched why give them your money and the credit for just reacting to another site and punish the other site that has taken the plunge.
What you may find is other sites dropping their prices on these sorts of items less and less and you will end up paying more in the long run for the like one day quicker delivery from Amazon.