How does google know if rich snippet reviews are fake?

[wlingke]

According to: https://developers.google.com/structured-data/rich-snippets/reviews - all someone has to do is add in some html code and write the review. How does google do any validation on whether these reviews are legitimate or not?

[MiriamEllis]

Hi Lingke!

Good feedback from everyone here. I just wanted to be sure to throw into the mix that fact that John Mueller specifically stated last December that Google does not want markup on on-site testimonials:

https://productforums.google.com/forum/#!topic/webmasters/wY1vF2RRos4/discussion

More on this here:

http://www.localsearchforum.com/google-local/26385-say-what-google-says-dont-add-review-markup-your-customer-reviews.html

[rjonesx. 0]

My guess is that Google is getting better and better at detecting false review data. There is a lot of academic research around this area, particularly in accounting fraud, where patterns created by humans to appear random do a poor job of actually representing standard data. A popular example of this is called Benford's Law where leading digits of certain data sets (like electricity bills) are more likely to be lower digits (starting with the number 1, for example). When people try and fake the data, they don't tend to follow this law.

Google has huge data sets on validated reviews and known-fraudulent reviews. If there is a way to detect unbelievable reviews, you got to believe Google is working on it.

That being said, this is probably the best reason not to start posting fake reviews... it's illegal.

[CleverPhD]

The answer here is "no" Google has no idea if they are fake or not.  Google may be able to tell if the reviews are duplicated on other sites (as it can do with other content) and so could in theory not rank the pages with the duplicate content/reviews. A common recommendation we give to a small business is to not copy reviews from other sites for this reason, and usually reprinting reviews are a violation of the TOS of the review site.   I would speculate that Google could look at the overall reputation/authority of a site to see if they display snippets, but that it really only a guess on my part.

The only thing that Google can validate, to a degree, are the reviews that come through Google+ type profiles.  They can do things like see if a profile was created, gave a single positive review and then the user never logs in again. That would obviously be a suspect pattern and there are for sure other examples. I have seen Google sometimes do things like look at a business, see if it has a validated Google Local profile and if they do, Google will pull in reviews from review sites and display them in the Google local cards.  There is a bit of validation there as the business has taken the time to verify itself in Google Local.

That said, I would say many users can tell a fake review a mile away.  We bring focus groups onto a review site I help with and they can tell when things look "off".   I would not waste my time with fake ones for that reason alone.

Also, if you do have legitimate reviews, you do need to make sure the markup is correct if you want the snippets to show in the SERPs.  If your markup is not valid the snippets will not show up. The Rich Snippets testing tool can help with this

https://developers.google.com/structured-data/testing-tool/