(MUNIcipal Wi-Fi) A Wi-Fi hotspot run by a city or other municipality. The service can be free or paid or a mix of both. For example, in public parks and libraries, the service may be free, but a monthly fee may be required in residential neighborhoods. Muni Wi-Fi networks emerged in the 2005 time frame with Philadelphia and San Francisco being the two largest cities at the forefront. The Business Model Is Key Earthlink built the Philadelphia and San Francisco infrastructures, but dropped the projects in 2008. Philadelphia residents had not signed up for the low-cost service in sufficient numbers, and the system needed more routers mounted on public utility poles than initially thought. Although Google planned to sponsor the San Francisco venture through advertising, Earthlink management changed direction. Other Muni Wi-Fi projects were also abandoned due to insufficient user subscriptions. On the other hand, municipalities that used the network for governmental services and guaranteed a certain amount of financial support have been successful. See Wi-Fi and Sidewalk Labs.