In Bangalore, the Volvo bus service pays back its costs by selling space inside the bus
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/advertising-pays
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/down-earth
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng-buses
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/transport
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/public-transport
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi