Socialamedia is ”a groupaof Internet-basedaapplicationsathat build on theaideological andatechnological foundationsaof Web 2.

0, andathataallow the creationaand exchange of usergenerated content” (Kaplan & Haenlein, 2010). In the past decade, wewitness the rapid development of social media in the cyber world, which bringssignificant impacts to our daily lives. This rapid development stimulatesresearch efforts in studying the impacts of social media to different facets inthe society through the theoretical lens of information systems (IS) (forexample, Gnyawali, Fan, and Penner (2010), Pai and Arnott (2013), andRansbotham and Kane (2011)) and marketing (for example, Naylor, Lamberton, andWest (2012)). At the moment, there is no formal classification of the types ofInternet-based applications included in social media. However, ConstantinidesandaFountaina(2008) suggestclassifyingasocialamedia into fivecategories, i.e.,a(i)blogs, (ii)asocialnetworkasites (foraexample,aFacebook and Google+),(iii) contentacommunities(foraexample,YouTubeaandWikipedia), (iv) e-Forums, and (v)acontentaggregators.aAmongstthese fiveacategoriesof Internet- basedaapplicationsin social media,asocialnetwork sites (SNSs) is the most popular one nowadays.

The most successful SNSis Face book, which has a market value of around $61 billion as at 28 March2013 (Yahoo!, 2013) and over 1 billion users all over the world (Wikipedia,2013). SNSs allow individuals to build up personal Webpages to disseminatetheir information, and communicate with their friends in real life as well asin the cyber world. Firms can do a similar thing with a fans page. SNSs have ahuge potential for marketers to develop the brand image of their productsthrough using the Word-of-Mouth in cyber world (i.e.

, electronic Word-of-Mouth)in an inexpensive way. Therefore, in recent years, some studies have beenconducted to investigate into how electronic Word-of-Mouth is developed insocial media (Cheung & Thadani, 2010).