This picture shows how this edu backlinks work :

Edu backlinks – Bronze Package , is intended for new sites which have just built. In this package, you will get :

• 10 Profile Edu backlinks
• 2 In Content/Contextual Edu Links
• 240 Social Bookmarks for your edu pages
• up to 3 backlinks per page
• All Dofollow backlinks
• Total up to 36 Edu Backlinks and 240 Bookmarks
• Price : 27.5 USD