The information in Shopping Ads is now available to all retailers (free of cost) and can be submitted directly to Google in real-time, not just by adding schema markup to your site.
Please visit Search Engine Land for the full article.
Search Engine Land: News & Info About SEO, PPC, SEM, Search Engines & Search Marketing https://searchengineland.com/google-merchant-center-to-deliver-real-time-search-results-313226