Previously it was only possible to get Google Local review stars if you were using AdWords Express. Typically they would show if you had at least 3.5 stars and some minimum number of reviews. In the case of seller ratings that number is 30. Starting today, ratings from your Google My Business listings are eligible to appear in ads with location extensions enabled on desktop and tablet. Local ratings make your ads more useful to consumers searching for local information, and can improve your ad performance. To showcase your Google My Business reviews in your ads, make sure to have location extensions enabled in your account. Get the full story at Blumenthalsl and Google