In-Page Promotion
Your product is one of the most effective channels for product engagement, especially compared to email inboxes. The balance, however, is not overwhelming users or creating unnecessary friction that prevents the user from accomplishing what they signed in to do.
In this example, Github uses embedded promotions to educate users on features they don't have access to yet in an attempt to up-sell. This particular promotion shows deep in the product on the Repo settings page. What they've done well here is that the up-sell is contextual to the product space the user is working within, and it's placed inline at the bottom of the page as to not be overly disruptive or in your face.
