“Carry pets on the Escalator”

Said the sign at the escalator.
And both Mark and Spencer waxed wroth.
For most of the shoppers carried neither cats, nor dogs.
So they set up a pet department to rectify the situation.
And although the shoppers bought pets in large amounts,
they were reluctant to take them shopping, violating the Escalator Rule once more.
Mark and Spencer now had their barbed hooks of motivation entangled in the fishing line of uncertainty.
They contemplated several possibilities including genocidal elimination of the stereotypical shopper.
However, without a shopper on an escalator cats or dogs will never be carried.