Two terms reside at the center of the ongoing quest for measurable metrics and estimating ROI within the social media arena – reach and engagement. “Reach” is a measurement relic of traditional advertising effectiveness such as TV or radio spots. “Engagement” is the latest buzzword (pun intended) for discussing the efficacy of social media marketing efforts. At the heart of any discussion of reach and engagement is the ongoing challenge of informed media planning across channels. At the end of the day, planners seek understanding of the return they are getting across channels. With the explosion alternative online and mobile channels, this task has become exponentially difficult.

Offering up a high-level, opinionated, and non-technical discussion of these two concepts is the subject of this post. Are they two sides of the same theoretical coin or polar opposites? As with many things, the answer to this question lies somewhere in between.

Part One will discuss Reach; Part Two will focus on Engagement.

Reach

Reach can be generally described as the number of people who are exposed to advertising or brand messaging. The pure reach numbers resulting from Dr. Pepper’s offer of a free can of soda if Guns n’ Roses was able to release their “Chinese Democracy” album in 2008 (as well as from the continuing press surrounding the announcement) are no doubt quite attractive.

However, reach is more often used to estimate the exposure of traditional (online and offline) marketing and advertising communications (as opposed to PR efforts).

Offline and online reach definitions are conceptually similar. Online reach is generally defined as the percentage of audience being touched by messaging (while frequency is the number of times that message has reached this audience). Gross rating points (GRP’s) – the product of reach and frequency – are the foundation of traditional advertising effectiveness and are increasingly held up as the focal point of online reach as well.

However, the explosion of marketing channels is one challenge facing any online estimation of audience reach. Another challenge associated with any discussion of reach is whether and if the right audience is being targeted with digital marketing communications. Thus, a growing emphasis on the engagement concept – what it is, what it means, and how it might be measured.