这引起了人们对于广告作用的怀疑。

This raises doubts about the point of advertising.

《柯林斯英汉双解大词典》

一份负面的保证，能起到相反的广告作用。

A negative guarantee. The opposite of an advertisement.

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那样的负面的背书，会起到相反的广告作用。

That kind of negative endorsement, it's the opposite of an advertisement.

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And it's really, the significance of advertising is getting friends to talk about a brand, right?

当你和朋友们聊起一个品牌的时候，广告的作用越来越明显了，不是吗？

SNS和广告的关系 - SpeakingMax英语口语达人