Pages or products rankings depend on how long it has been on the site has been live and if google has indexed it yet. When first launching the site google crawls our website and sitemap to retain all the information and content we provide, then it will periodically return to crawl and update its results.
Google Search Results Updating
The only way to expedite google updates is to make sure you update your pages often, that way when it does return google will see something new every time. Creating new pages and content is the most effective way to make your website stronger.