The sleeper effect refers to the phenomenon that the communication effect of source credibility will change over time. That is, after a period of time, the positive effect brought by high credibility sources is decreasing, while the negative effect brought by low credibility sources is changing towards the positive effect.
According to the above definition, which of the following belongs to the sleeper effect?
Celebrity advertising can only increase sales in the short term. Over time, the sales of products will decline rapidly.