By Paul Carsten BEIJING (Reuters) – Baidu Inc launched on Wednesday a service that helps retailers advertise on the smartphones of nearby users as Chinas dominant search engine company expands its location-based technology to drive growth. Baidu currently makes most of its income from desktop-based search advertising and has lagged peers such as Tencent Holdings Ltd in capitalizing on the popularity of mobile internet in China, the worlds largest market for smartphones. In the mobile era consumer behavior is changing, and the mobile Internet has given us new businesses and opportunities, said Robin Li, Baidus chief executive, during the launch of the Baidu Connect service.