Well obviously...
Like - Duh. Of course sales would be down. Everybody with a 3D Printer is busy printing out additional 3D Printers. So if you want to make money, you need to be flogging cartridges of recursively-named '3D Printer 3D Printer Paste'.
But even that is short term, because obviously the punters will start 3D printing out replica cartridges of your '3D Printer 3D Printer Paste', so you'd want to get ahead of the trend and start flogging cartridges of '3D Printer Cartridge of 3D Printer 3D Printer Paste'.
;-)