This is a specific article about leveraging custom product attributes.
Nosto supports adding stars – as in product review rating – to the templates of
recommended products. Here is how its done:
Using Default Templates
If you use default recommendation templates, simply flip the switches under Template Settings > Properties and disable or enable ratings and/or reviews
Using Custom Templates
Use our tag fields rating_count and review_count pass the rating results on product page, as you would when you pass us other product variable such as price. This will be probably a number between 1 and 5.
<span class="review_count">20</span>
<span class="rating_value">3.0</span>
2) Inside the template section, this variable is now available for use.
3) Create the actual stars using CSS based on the tag field variable. http://css-tricks.com/star-ratings/