I share a toothbrush charger with my wife. When my brush isn't on the charger it leaves behind water spots on our black granite vanity which shows everything. It also traps water underneath it which can make for a gross and unhygienic buildup under base of the toothbrush. I wanted a little tray to direct drips the excess water back into the sink and with a little airgap that would let the base of the toothbrush dry out between uses and not become gross. It's also easier to clean the little tray than it is to break out the razorblade and scrape the haze off the granite.