profit or greed?

is there a difference between profit and greed? with "the cost" of crude oil going down, why are companies slow if lowering the price? they are quick to raise the price when the cost goes up, or even "might" go up - here is a bit of news:

Exxon Mobil Corp. rewrote the corporate record books Thursday as the oil company's third-quarter earnings soared to almost $10 billion and it became the first public company ever with quarterly sales topping $100 billion. Anglo-Dutch competitor Royal Dutch Shell PLC wasn't far behind, posting a profit of $9 billion for the quarter. [and there is so much more...]