Does anyone know what the delay is for stars to appear in the SERPs for a page that has reviews and the schema.org markup?
I implemented the markup on an e-commerce site about a month ago, but only 1-2 results (out of the first 500) show stars in the SERPs.
These pages have been crawled since the markup was implemented, as confirmed by the date of the cached version and the fact that Google Webmaster Tools shows the correct count in Structured Data. The markup is also correct according to Google's testing tool.
So it seems obvious that Google knows about this markup, but it isn't generating anything in the SERPs (yet). Any ideas why?