Aiming for satisfying the requirement on quality of experience (QoE) for many important applications, we proposed a QoE-oriented WLAN which employs channel access permission control and dynamic network reconfiguration. For practical system deployment, it is important to assess the upper performance limit of the system. This letter introduces a metric "effective area throughput" (EAT): it is the area throughput summed up among the applications which achieve the throughput for satisfying their QoE requirements. This letter then derives the maximum expected EAT of the QoE-oriented WLAN based on a random sampling method. Through numerical evaluation, it is confirmed that the proposed derivation method provides a valid expected EAT for WLAN with several tens of nodes in a tractable computational complexity. It is also confirmed that the QoE-oriented WLAN has potential to increase the EAT compared with the conventional WLAN.