its general keywords not related to specific location so i think they did it to get better ranking, its more easy to link from main domain to lets say 100 categories than linking to 100 categories x 100 cities =10,000
what makes me think that its cloaking is for all visitors they do provide specific location but not for google bot, for google bot they showing page with ads around the world, but google bot as every other bot have an ip which related to specific location