Ever wonder why printers are suspiciously cheap but ink cartridges cost approximately one kidney? Or why your Keurig machine was affordable but those little K-cups add up to basically brewing liquid gold? Congratulations, you've been razor-bladed. This business model has a simple, slightly evil genius behind it: Sell you the main thing cheap (or even at a loss), then make all the real  money on the refills, accessories, or consumables you'll need to keep buying forever. It's