Its all about distributorship. Biz. Big biz at that I'm sure. There are small companys that carry both... and get products from both Horizon and Tower.. but Tower and Horizon are the suppliers, not retailers, other then mail order. You notice neither one has a store front... When you get down the chain though, you'll see(I'm sure you have), the smaller retail outlets carry both/all brands.. Take HobbyTown, they sell it all, just as many smaller outlets do.. but when you climb the chain, its Tower and Horizon that supply it... and theres probably many legalities involved.. as each radio and accessory manufacture makes many components for other industries too... . big buck stuff.