These after-school classes could first of all increase teachers 'incomes. Furthermore, they were more flexible in terms of the progress levels expected and the teaching materials which could be used. As one buxiban educator observes, "To put it not so nicely, you had more latitude to voice opinions about current events, or slightly' off-color 'humor, that you couldn't express in public schools."
教師在校外兼課，一方面可增加收入；另一方面，在補習班教課時，受到進度、教材的限制較少，「說得不好聽，在學校不能發表的對時勢等的議論，或是帶點『顏色』的提神笑話，在補習班也較開放地談」，一位補教界人士指出。