A retailer that discounts regularly changes shopper behaviour in a way that persists after the promotion ends. The change works against the retailer and compounds over time.

Reference prices adjust downward

Shoppers form an internal sense of what a product costs from the prices they have encountered, and repeated promotions pull that internal figure toward the discounted level.

The list price then reads as inflated rather than standard, and buying at it feels like an error rather than a normal transaction.

Once that adjustment has happened, the full price stops functioning as a price and becomes the number that promotions are measured against.

Deferral becomes a learned strategy

When promotions arrive on a recognisable cycle, waiting for the next one carries a known and short cost, so postponement becomes the sensible default.

Shoppers do not need to track the cycle deliberately. Repeated experience of a reduction arriving shortly after a full-price purchase is sufficient to produce the behaviour.

The result is that promotional periods absorb an increasing share of category volume while the intervals between them grow progressively quieter.

The escalation is self-reinforcing

As full-price volume falls, the promotion has to work harder to hit the same total, which means deeper discounts or longer promotional periods.

Both responses reinforce the underlying expectation, and the next cycle begins from a weaker position than the last.

This is the mechanism behind categories where the advertised price has become almost theoretical and virtually every unit sells on some form of offer.

Competitors are pulled in

Once one seller in a category promotes heavily, others lose volume during those periods and typically respond with promotions of their own.

Because the behaviour change happens at the category level rather than the retailer level, the training effect applies to everyone regardless of who started it.

Unwinding it requires the whole category to move together, which is difficult to coordinate and easy for any individual seller to defect from.

What limits the spiral

The pattern is checked where purchases cannot be deferred, such as immediate needs, replacements for failed items and time-bound occasions.

It is also weaker where products change frequently enough that waiting means buying something different, since the deferred purchase is no longer the same purchase.

Retailers exploit both by concentrating promotions on storable, comparable goods and holding firm on categories where the shopper has no realistic option to wait.