Amazon announced a new Login with Amazon service for websites, apps and games, which lets users login using their Amazon accounts. The company says it reduces sign-in friction and can drive higher customer engagement and conversions.

Obviously the feature would compete directly with offerings from companies like Google, Facebook and Twitter.

“Login with Amazon enables app developers and website owners to leverage Amazon’s trusted sign-in solution, allowing them to focus on providing a great experience for their customers,” said Michael Carr, Amazon Vice President, eCommerce Services. “Amazon customers now have a hassle-free way to quickly and securely sign-in to apps, games and websites, without having to remember yet another password.”

Amazon subsidiaries Zappos and Woot have been using the Amazon login feature, and the company says it has seen “significant” customer adoption. Zappos in particular saw 40% of its new customers choose to sign-in with an Amazon account. On Woot, new customers picked Login with Amazon two times more often than any other social login on the site. Those customers, Amazon says, had the highest conversion rate.

Amazon appears to be looking to capture users while they’re on properties across the web more than ever before. They also recently launched a “Send to Kindle” button for content, enabling users to send articles for later reading on their Kindle devices/apps.

You can find all the necessary documentation for Login with Amazon for web, Android and iOS here.