Overselling can refer to selling more of something than exists or is required, or exaggerating a product's merits.In the tech world, overselling often occurs when companies overstate the capabilities of their products.Vapourware is a product that doesn't exist or fulfill stated technical capabilities, like Google Glass.Unobtanium is a desired material or specification that doesn't currently exist, driving innovation in aerospace.Misleading overselling can lead to scandals, like Volkswagen's diesel emissions fraud.While overselling can attract interest, it can damage a brand if the product fails to deliver as promised.The pursuit of unobtainium drives technical progress, as seen in advancements like single crystal turbine blades.Vapourware can create opportunities for innovation and lead to the development of new technologies and solutions.The case of Google Glass highlights how failed products can still contribute to advancements in other areas.While overselling can have negative repercussions, it can also spur technological advancements and market competition.