An advertising consultant and researcher, Russel Colley, proposed DAGMAR, an acronym for Defining Advertising Goals for Measured Advertising Results, back in the 60s. This model, a classic from marketing literature, has stood the test of time even in this age of social media when marketers and practitioners think about evaluating social media investments. I modified the DAGMAR model to suit the present day popularity and fervor of social media marketing.
Impressions are the online content customers see; expressions are what customers do (like, +1, comment, share) after they see the online content. Brands should recognize social media impressions as a nexus to expressions in their overall marketing efforts. It is only through dynamic content, which will engage customers, that brands can drive customers to act, and ultimately co-produce relevant content for profit and growth.
In this age, Sociology is not an elective course. Social media is a great equalizer, and it is leveling the field for those brands that can engage, influence, and lead customers. Today, the consumer ecosystem itself is a content and marketing machine that gets the word out to prospects and suspects in the world. I hope this macro-level tool throws much needed light on how you look at brands and their relationship with social networks.
Recommended reading: http://blogs.hbr.org/cs/2011/04/coca-colas_marketing_shift_fro.html?cm_mmc=email-_-newsletter-_-marketing-_-marketing052411