ks ▁collect ▁much ▁of ▁their ▁re venue ▁from ▁ad mission ▁fe es ▁paid ▁by ▁guests ▁att ending ▁the ▁park . ▁Other ▁re venue ▁sources ▁include ▁par king ▁fe es , ▁food ▁and ▁be verage ▁sales ▁and ▁sou ven irs . ▁ ▁Pract ically ▁all ▁am usement ▁par ks ▁operate ▁using ▁one ▁of ▁two ▁ad mission ▁principles : ▁ ▁Pay - as - you - go ▁In ▁am usement ▁par ks ▁using ▁the ▁pay - as - you - go ▁scheme , ▁a ▁guest ▁enters ▁the ▁park ▁at ▁little ▁or ▁no ▁charge . ▁ ▁The ▁guest ▁must ▁then ▁purchase ▁r ides ▁individually , ▁either ▁at ▁the ▁att raction ' s ▁entrance ▁or ▁by ▁purch asing ▁ride ▁tick ets ▁( or ▁a ▁similar ▁exchange ▁method , ▁like ▁a ▁token ). ▁ ▁The ▁cost ▁of ▁the ▁att raction ▁is ▁often ▁based ▁on ▁its ▁complexity ▁or ▁popular ity . ▁ ▁For ▁example , ▁a ▁guest ▁might ▁pay ▁one ▁ticket ▁to ▁ride ▁a ▁car ousel ▁but ▁four ▁tick ets ▁to ▁ride ▁a ▁roll er ▁co aster . ▁ ▁The ▁park ▁may ▁allow ▁guests ▁to ▁purchase ▁a ▁pass ▁providing ▁un limited ▁adm issions ▁to ▁all ▁attra ctions ▁within ▁the ▁park ▁for ▁a ▁specified ▁duration ▁of ▁time . ▁ ▁A ▁w rist band ▁or ▁pass ▁is ▁then ▁shown ▁at ▁the ▁att raction ▁entrance ▁to ▁gain ▁ad mission . ▁ ▁Disney land ▁opened ▁in ▁ 1 9 5 5 ▁using ▁the ▁pay - as - you - go ▁format . ▁Initial ly , ▁guests ▁paid ▁the ▁ride ▁ad mission ▁fe es