以下是引用liliy4gmat在2005-7-20 9:48:00的发言:1。fallacy analogy between differeent towns. 2. on-line survy is uncompelling. participators are limited readers of sth 3.switch to PDQ increase the cost of dilivery but can not highly increase the sales of PDQ.
For no. 3, switching to PDQ doesn't increase the cost of delivery, because it's free delivery. However, the author fails to mention whether selling PDQ will profit more than current pissa. That leaves the author's conclusion on more profit made from switching to PDQ ungrounded. |