“A content upgrade is bonus information that elaborates on or complements a piece of content the reader is already interested in. The bonus is both highly valuable and in context with the page’s content so we gate the bonus by asking for an email address, a Facebook share, a tweet, or an email to a friend. In other words, a content upgrade is a valuable offer created to get a visitor’s email address or get them to promote you.”
A content upgrade is when you complement a piece of content with other highly valuable content your reader may be interested in—like adding a video tutorial to the end of an article about baking bread. Reading is great, but sometimes people are willing to subscribe to content if it means more details or information.