If I write a review, on which sites will it be displayed?

Your review will be displayed under the product you commented and on the website where you have left it.

Of course if that website has Rivio embedded on multiple pages, your review might appear on those pages too. Additionally, if your review is voted helpful by the community, Rivio's smart review aggregation engine might decide to display it on other, third-party sites too under the same product that you had your valuable opinion about.

Webshop owners have limited rights to moderate reviews, but if the review is inappropriate / mistakenly written for the wrong product, they are allowed to do so. So in rare cases reviews are moderated out by the webshop admins, and thus such won't appear even on the very webshop you wrote it to.