Internet business never shuts down. It runs 24 hours a day, 7 days a week and captures traffic across the world at different time from different countries. This is global traffic that comes from your efforts sometimes may be useless for your niches especially if you want to target a particular groups, region or subject you will be request targeted traffic.
While approaching global traffic is quite easy, targeted traffic requires different skills than ordinary SEO practices. A well planned marketing strategy and using appropriate SEO practices a site can receive targeted traffic from a particular field though it may take time and more efforts than regular theories.