This chapter reviews the literature to derive a set of key drivers of customer engagement (CE). The review is conducted by assessing four comprehensive deductive models involving many constructs that have been previously proposed or tested as CE drivers. Following the review, we introduce an indicative matrix to measure the effectiveness of a CE marketing initiative proposed for any product or brand. The instrument is a useful tool for managers to help predict the level of success of a CE marketing strategy might attain. Several existing models of CE drivers have been proposed by previous researchers. Combining and juxtaposing select models of CE drivers and strategies helped inform us regarding the primary design elements of a CE marketing strategy that in turn generated an applied matrix of Customer Engagement Marketing (CEM) effectiveness. The identification and application of essential design elements in developing the instrument also lend it the ability to identify the required aspects of a strategy built to deliver CE with a brand.