为何不加冠词?Internet shopping on Nov.11th

If you think that Internet shopping on Nov.11th gets you a better deal,then you are fooled.
首先让我们假设前半句是这样的
If you think that shopping on Nov.11th gets you a better deal
名词 shopping 前不加冠词,
短语 internet shopping 的 internet 是 形容词（修饰 shopping）,
因此同样不加冠词.
再举个例子：
If you think that skating makes you lose weight
skating 前面无冠词,同一个理由
If you think that ice skating makes you lose weight
ice skating 前面也无冠词.