Respuesta :

They provide celebrity encouragement to persuade the consumer. 
In our generation where celebrities have power to influence buyers, their comments can be powerful tools to make people buy whatever products.
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Answer:

Because testimonials can influence people.

Explanation:

Advertisers use testimonials because testimonials can influence people. This is because the testimonials show people who have had experience with the product and have had positive experiences, ie, it is proof that the advertised product is of quality and delivers what it promises. This gives the merchant credibility and can increase their sales significantly because some consumers only buy the product after hearing positive testimonials about it.