User engagement is at the heart of any design philosophy. With the user-centred approach, designers are always on the lookout for new techniques to enhance user engagement with products, websites and programs like online games. The objective is to make a product easy and enjoyable for users to use. Making a product easy to use and enjoyable enhances user experience (UX) leading to increased user engagement. Even traditional online card games like pool rummy have enhanced user experience. The secret lies in gamification in the UX design, which has assumed high importance in recent years. Although a very modern concept, it does have a far-reaching impact on the understanding of user preferences and increasing user engagement.
http://www.forbesindia.com/article/brand-connect/gamification-in-ux-design-for-enhanced-user-experience-and-engagement/52075/1/