Controversy surrounds the topic, but the guidelines are clear if you bother to read them. The rules aren’t complicated:
Google does not allow you to have a kiosk or a review station in your business.
And forbids writing a review on behalf of another person.
Source: https://support.google.com/business/answer/2622994?hl=en
Yelp doesn’t want you to ask for reviews either.
Source: http://www.yelp.com/guidelines
Source: https://biz.yelp.com/support/review_solicitation
Don’t post your Yelp reviews on your own website. Yelp doesn’t allow you to use their content. This language has been in place since 2011.
Source: http://www.yelp.com/static?p=tos_archived
Click to download our printable Terms of Service and Content Guidelins Cheat Sheet