New media and mobile technologies have opened up numerous 'unregulated spaces' (Sebba, 2009b) and public spheres for self expression, interpersonal interactions as well as the transnational transcultural flow and fusion of ideologies (Pennycook, 2007). The discursive and interactive possibilities of mobile and Web 2.0 technologies make computer-mediated communication (CMC) platforms techno-linguistic environments for virtual deliberation and discussions. Online multilingualism and contact phenomena easily flourish in such contexts. Many Nigerians at home and abroad are embracing the CMC technologies to interact with one another, to negotiate profitable ideas for the betterment of Nigeria and to redress endemic socio-political issues. This study examines the linguistic construction of textual messages by Nigerians and the sociocultural manifestations of 'Nigerianness' (Chiluwa, 2008) and Nigerianisms in digital discourse. The dissertation is divided into four parts, each comprising two chapters. Part I introduces the subject matter and research focus, with an examination of language and identity in the typographical representations of Nigerianness by theoretically using relevant aspects of discursive work (e.g. Benwell & Stokoe, 2006; Bucholtz & Hall, 2005; De Fina, Schiffrin & Bamberg, 2006; Le Page & Tabouret-Keller, 1985; Llamas & Watt, 2010); Part II is concerned with the theme of Internet code switching and language crossing; Part III addresses the dialectical connection of language, new media technologies and politics; while Part IV presents the questionnaire survey results and research findings. The study innovatively examines language contact features in Nigerian CMC in terms of Bourdieu's (1977) economics of linguistic exchanges and the Faircloughian (1992) application of intertextuality in the Bakhtinian spirit. By linguistic marketing is meant discourse as a vehicle for 'promotional acts' and for 'selling' particular cultures and ideologies to multicultural and multilingual readers/audiences. One interpretation of this is in terms of asserting language rights and linguistic equality. Therefore, the use of Nigerian languages with Nigerian Pidgin online is promotional and for existential negotiation. This results in language mixture which is an instantiation of freedom of speech, freedom of switch and the freedom to switch. The underlying pragmatic motivation for top-down language mixture and alternation in Nigerian virtual discourse is attention-getting with the aim of inducing an interdiscursive writer-reader cognitive as well as communicative interactions. Other pragmatic functions of code switching discussed in the study include allusive textuality, amusing phaticity, anticipated interactivity, affective expressivity, and audience affiliation or alienation. Thus, intertextuality is an explanatory technique for investigating previously unexplored phenomena in digital code switching. Rampton's (1995) conceptualisation of language crossing is used to explicate the graphemic representations of variation in Nigerian English phonology. Additionally, for the sake of explanatory exigency, relevant aspects of speech acts theory (SAT) (Austin, 1962; Searle, 1969) are fused with critical discourse analysis (CDA) for the construction of our data-derived, election-oriented, politico-pragmatic tweet acts, in terms of what we call Good Governance Maxims (GGM). Finally, there are two types of data employed in the study: (i) corpus (INEC i.e. Informal Nigerian Electronic Communication with PLANET - Purposeful Language Alternation in Nigerian Electronic Texts) and (ii) questionnaire survey. The random sampling of 1,154 Nigerian undergraduates offline illustrates how computer-mediated discourse analysis (CMDA) can be supplemented by a sociolinguistic survey in what Androutsopoulos (2006:424) calls “the observation of Internet use in offline social spaces” through a blend of on- and offline ethnography.