, ▁after ▁which ▁TV GN ▁( now ▁Pop , ▁and ▁originally ▁a ▁television ▁list ings ▁service ▁formerly ▁known ▁under ▁several ▁names ▁including ▁the ▁Pre vue ▁Channel ) ▁began ▁air ing ▁same - day ▁repe ats ▁of ▁some ▁network ▁so aps . ▁ ▁Network s ▁use ▁prof its ▁from ▁commer ci als ▁that ▁run ▁during ▁the ▁show ▁to ▁pay ▁the ▁production ▁company , ▁which ▁in ▁turn ▁pays ▁the ▁cast ▁and ▁crew , ▁and ▁keeps ▁a ▁share ▁of ▁the ▁prof its ▁for ▁itself ▁( network s ▁sometimes ▁act ▁as ▁both ▁production ▁companies ▁and ▁distrib utors , ▁though ▁due ▁to ▁the ▁vertical ▁integration ▁of ▁networks ▁and ▁major ▁media ▁companies ▁since ▁the ▁ 1 9 9 0 s , ▁production ▁arms ▁operated ▁by ▁the ▁broadcast ▁networks ▁have ▁largely ▁been ▁absor bed ▁into ▁the ▁existing ▁production ▁arms ▁of ▁their ▁corpor ate ▁parents ). ▁As ▁advert ising ▁rates ▁are ▁based ▁on ▁the ▁size ▁of ▁the ▁audience , ▁meas uring ▁the ▁number ▁of ▁people ▁watching ▁a ▁network ▁is ▁very ▁important . ▁This ▁measurement ▁is ▁known ▁as ▁a ▁show ▁or ▁network ' s ▁ratings . ▁S we eps ▁months ▁( which ▁occur ▁in ▁November , ▁February , ▁May , ▁and ▁to ▁a ▁less er ▁extent ▁July ) ▁are ▁important ▁land marks ▁in ▁the ▁television ▁season ▁– ▁ratings ▁earned ▁during ▁these ▁periods ▁determine ▁advert ising ▁rates ▁until ▁the ▁next ▁swe eps ▁period , ▁therefore ▁shows ▁often ▁have ▁their ▁most ▁exc iting ▁plot ▁develop ments ▁happen ▁during ▁swe eps . ▁ ▁Sh ows ▁that ▁are ▁successful ▁with ▁aud ien ces ▁and ▁advert is