I think this shows a significant disconnect between the ostensibly-wealthy managers that cooked up this genius marketing ploy and their customers: if the managers want an intercontinental flight, they just book it at whatever the current price is, because £600 is chump change for them and does not motivate them to invest time into looking for deals. It thus naturally never occurred to them that anyone would even think about buying the cheapest qualifying vacuum, even though they don't need one at all, just to get an awesome deal on flight tickets - basically it's flight ticket buying for £120 with the catch that you must dispose of a cheap vacuum. Anyone to whom those £600 worth of flights appear as a considerable value will immediately come to this conclusion, whereas if £600 means nothing to you, you'd never even think about putting up with the hassle.