This is true but do you remember the liter price you paid for laundry detergent or do you remember that you bought it for $14?

I'd wager that most people are in the latter, even if they are completely informed of shrinkflation.

For me the liter price I use when trying to figure out if a sale of the 1 gallon is actually cheaper than the 2 gallon normal price (or whichever units of measure for an item).