Here's another quiet update from Google, which will a delight for website owners. Instead of 4-6 sitelinks, webmasters can now add up to 10 sitelinks for a domain name based search query on Google.
When tried searching for amazon.com on Google, the top result came along with 10 sitelinks.
However, ten sitelinks were not returned on searching for brand name Amazon on Google.
So, there are high chances that the new update is restricted to domain search.Google Now Shows Up to Ten Sitelinks for Domain Search!,