Of course you don't know that the company is real, that the person is who they claim they are, nor do you know whether they have an advertising contract with the person they recommend.

Also there is no need for the caricature, there are certainly more sincere sounding ways to recommend someone than following the standard testimonial script:

"I am [person] with [relevant characteristics or employment]. I had this exact [problem] and thankfully [advertiser] was able to help me.

When I first got this [problem] I was [emotionally affected in a personal and relatable way]. Other companies told me they had better [price/solutions]. Thankfully I found [advertiser] and they were able to help me like no others. [Short snippet demonstrating advertiser holds values important to the target demographic (price/effectiveness/privacy/dedication/...)]. I would definitely trust them again if [problem] happened again. [Prompt for you to trust them and give them your business.]"

Here are testimonials for cash for gold for comparison: https://vimeo.com/35628298