"If I buy this, I'll save money. It's, like, seventy percent off."
A simple ruse, yet like most of its kind, remarkably effective. What makes it most effective, sociologically speaking, is not actually the more direct expression of it, in the sense of convincing people to buy something they would not have otherwise bought. For example, we may be living a life, living a day, planning on hanging around the house (dialect for not going to a goods repository and trading currency for something as a form of amusement; although that gap has already mostly been bridged, the saying still has a trace of non-purchasing left), and not otherwise intending to buy anything. We can modify this behavior by making the purchase--literally subtracting from resource-acquisition capabilities--become a necessary, helpful, vital, resource-acquisitive act, by creating the illusion that the purchase is actually a necessary saving and/or acquisition of resources. Ergo the implication that by losing money, one is gaining money--sic.
We see the effectiveness of this technique magnified across history by the theft of credit for accomplishments during historical periods, wherein a prisoners' having acquired something is credited to the keeper. It's an easy trick, in the sense of assigning an anticipated value of zero to the time period in question, then crediting the desired authority with anything greater than zero. These assumptions made, the greatest bar to progress becomes the cause of progress. Whether mob-rule, cohort rule, or sales for things which wouldn't have otherwise been purchased, without the ability (or desire) to discern that the voyage might not have occurred, or something to have been done instead in the interlude, the liar's math is simple: any accomplishments must be the result of the act, even if the act itself was an act of subtraction. Socially, personally, we can pay witness to, if nothing else, media effectiveness, whereby one is saving money by spending it; where an act of self-harm becomes an act of self-aid by the illusory predicate of preexisting tech; by the exercise of body- or personality-conditions set long ago. Ergo the modern consumer actually does believe he is saving money by spending it.
We might liken the individual act in such a case to doublethink, except that doublethink implies a sophistication; an ability to believe both things, and thus to understand the truth of one while denying its truth. There is a similarity, for confronted clothing-savers would, at some level, understand the postponed schism between bank accounts and clothing, and thus, if forcibly educated with each purchase, would vocally admit an understanding that saving is not actually spending. Yet the true doublethinker simultaneously, completely understands, avows, and disavows, and therein lies his material genius. Two plus two actually is five, always, just as much as it can never be five, and there is never a moment of "breakdown" where a masterful doublethinker can perceive the contradiction. There is no contradiction, there never was one, and outrage at the implication that there might be such a contradiction is justified so thoroughly that, if you're not outraged, you're stupid.
The lesser stuff required of the masses, in the case of saving while spending, is less refined. We can buy things we wouldn't have bought, understanding the difference under cross-examination, yet putting it aside mentally for useful functioning. Obviously the end result of such behavior is trying, yet the historical variety is similar, but effects more because of our unfamiliarity with the passage of time. Ergo we may understand, vocally at least, that spending is not saving, yet when considering one millennia, rather than one afternoon or one lifetime, one's estimation of what would probably have been accomplished, compared to what was actually accomplished that we know of, controls the evaluation more than does one's evaluation of quality alone. During a period of dominance/ascension by a group, then, the prediction that achievement will be at zero, or near zero, controls one's evaluation of said group's effectiveness, more than does one's much-more-limited evaluation of the quality of the work alone. High expectations versus low expectations, perhaps. And in some sense, the girl with the new dress that potentially makes her look better than the last twenty-six will become upset, perhaps even good-naturedly, at the implication that the new dress was not needed, but if you set your baseline at "gonna spend at least $170 today" then shopping is saving.