Lack of confidence in the video game sector caused many retailers to stop selling video game consoles or reduced their stock significantly, reserving floor or shelf space for other products. This was the most formidable barrier that confronted Nintendo, as it tried to market its Famicom system in the United States. Retailer opposition to video games was directly responsible for causing Nintendo to brand its product an ""Entertainment System"" rather than a ""console"", using terms such as ""control deck"" and ""Game Pak"", as well as producing a toy robot called "R.O.B." to convince toy retailers to allow it in their stores. Furthermore, the design for the Nintendo Entertainment System (NES) used a front-loading cartridge slot to mimic how videocassette recorders, popular at that time, were loaded, further pulling the NES away from previous console designs.