The parable of the B&Q lightbulbs

Why do my local B&Q advocate the efficiency, eco-friendliness and cost saving of energy saving bulbs yet light up their entire display of 50 or so lamp shades with conventional inefficient, eco-hating, cost-increasing light bulbs?
And the moral of this story is?

(to be fair though they were saving a shed load of electricity by only having one checkout open despite the gargantuan number of DIYers battling queuefully to buy DIY-ey things)