“…Much of this content is published in social media because viral marketing uses a pre-existing social network to spread marketing information via word-of-mouth (WOM) among users of that social network (Yang, Yao, Ma, & Chen, 2010). As a result, research conducted with the help of data from virtual social networks is becoming increasingly common (Cvijikj & Michahelles, 2013;De Vries, Gensler, & Leeflang, 2012;Groeger & Buttle, 2014;Kim, Spiller, & Hettche, 2015;Ransbotham, Kane, & Lurie, 2012;Sabate, Berbegal-Mirabent, Cañabate, & Lebherz, 2014;Schulze, Schöler, & Skiera, 2014;Smith, Fischer, & Yongjian, 2012;Swani, Milne, & Brown, 2013), although authors stress that organizations have not yet been able to measure the effectiveness of strategies based on these environments (Hoffman & Novak, 2012;Kumar, Bhaskaran, Mirchandani, & Shah, 2013).…”