Buyers should prioritize Electronic Paper (e-paper) display technology, specifically 3-color (Black/White/Red) or 4-color screens, to ensure high visibility and low power consumption. The battery life is a critical metric; look for tags that offer 5 to 10 years of longevity based on 2-3 daily updates. Additionally, verify the transmission protocol, such as Bluetooth Low Energy (BLE), Zigbee, or Sub-G (433MHz/868MHz/915MHz), to ensure the signal can penetrate shelving and cover the entire store area without interference.