Hi @Steven B
You can't use collected/solicited individual reviews or sites that aggregate reviews. IMO, the name of this extension adds to the confusion - it's not for reviews in the general sense that most of us think of on the internet. It's closer to citing a source for a research paper. Add a snippet or quote in your ad extension and link to an original and legitimate source.
What you need is to link to an unbiased, unsolicited, "verified" 3rd party review, award etc...from a legit 3rd party source (Trade Journal, Accredited business review source, magazine etc...)
For some of our local service based clients, we use BBB ratings for example in Review Extensions.
You can read more here about what is and what is not acceptable.
Using Review Extensions: https://support.google.com/adwords/answer/3236114
Review Extensions Policy: https://support.google.com/adwordspolicy/answer/3197294
Hope this helps!
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