NEWSLETTER-2019-metin

120 NEWSLETTER 2019 product differentiation methods practiced by the platform, and the characteristics of the market where the platform ser- vices are offered. • There are at least two groups of decision-making units in the multilateral platform service markets that would like to establish commercial relations with each other through the platform, and there is a positive network effect between the- se decision-making units (changes in the value attributed to the platform by one side, which affects the other side in the same direction). For this reason, it is necessary to take into account the reaction of multiple decision-making units at the point of drawing the boundaries of substitutable products or geographical borders. • In the definition of the relevant product market, Sahibinden. com should be examined in terms of supply-side substitu- tability; whereas, in terms of demand-side substitutability, the behavior of undertakings that provide goods/services (car dealers, real estate offices, etc.) and the behavior of final consumers demanding goods/services should be examined by also taking into account the interactions between the two. • In the decision, in terms of the supply-side substitutability, it is stated that undertakings such as Sahibinden.com, Tasit. com, Arabam.com will not be taken into account given that they have no tendency towards providing alternative services due to their business plans/structures. In terms of demand- side substitutability, car dealers’ and real estate offices’, as well as the consumers’ (who seek to buy/rent and cars/real estate) reaction to the change in the price and/or quality of the service offered through the platform should be taken into account. • Offline platforms have not been included in the market des- pite Sahibinden.com’s counter arguments. For this purpose, it is stated that if the price level of the platform increases, or if the quality level of the platform decreases, the option for