Mobile search is an evolving branch of information retrieval services that is centered on the convergence of mobile platforms and mobile phones, or that it can be used to tell information about something and other mobile devices. Web search engine ability in a mobile form allows users to find mobile content on websites which are available to mobile devices on mobile networks. As this happens mobile content shows a media shift toward mobile multimedia. Simply put, mobile search is not just a spatial shift of PC web search to mobile equipment, but is witnessing more of treelike branching into specialized segments of mobile broadband and mobile content, both of which show a fast-paced evolution.
"Competition for the US mobile search market promises to be fierce, thanks to the large US online ad market and strong pushes by portals. By 2019, mobile ad spending will rise to $65.87 billion, or 72.2% of total digital ad spend", according to a leading market research firm; eMarketer. Depending on a researcher's particular bias toward telecom, Web or technology factors, the published forecasts for global mobile search vary from $1.5 billion by 2011 (from Informa Telecoms & Media) to over $11 billion by 2008 (according to Piper Jaffray).
Mobile search is important for the usability of mobile content for the same reasons as internet search engines became important to the usability of internet content. Early internet content was largely provided by portals such as Netscape. As the depth of available content grew, portals were unable to provide total coverage. As a result, Internet web search engines such as Google and AltaVista proved popular as a way of allowing users to find the increasingly specialist content they were looking for. In an international journal article, 'Exploring the logic of mobile search', Westlund, Gómez-Barroso, Compañó, and Feijóo(2011) outline a thorough review of research on mobile search usage, and also present an in-depth study of user patterns. They conclude that mobile search has started to change mobile media consumption patterns radically. They also emphasize that future developments of mobile search must be sensitive to the mobile logic.