Computer ink and ink cartridges are the most widely purchased and stocked item in any computer store. The demand for both black and color ink cartridges is higher than ever before and has led to a consumer frenzy of buying. The market for supplying ink to computer owners is lucrative to the tune of billions of dollars per year - yep it's really worth that much. Hard to believe that something so humble as the inkjet printer could be worth so much to so many eh?