Google published store ratings eligibility: ~100 reviews, 3.5 stars and reviews from the last 24 months

Google's store ratings overview for merchants now spells out the eligibility bar for showing seller ratings on text and Shopping ads: roughly 100 eligible reviews at a minimum 3.5-star average, drawn from the past 24 months. Ratings are calculated separately per country and reviews only count in the country they came from.

• Approximately 100 eligible reviews are needed before a store rating can show.
• Minimum average rating of 3.5 out of 5.
• Only reviews from the past 24 months count toward eligibility.
• Ratings are computed per country, and a review counts only within its country of origin, so multi-country advertisers can be eligible in one market and not another.
• Spotted by Hana Kobzova; Google's help pages are undated.