How can they sell a light bulb for 10p ?

Bought a few this morning in our local Tesc*s , at 15 watts , to replace a 60 watt conventional bulb .  Which makes it 4 times more efficient  by my arithmetic , and it is brighter than the original ( more powerful ) one . So I would have paid £2 or £3 for it on a purely arithmetic basis .

The fact that you can buy anything useful for 10p nowadays is a surprise , but I wonder how the economics work out . Are the people producing these in far distant shores being paid anything worthwhile , is the store concerned making a profit , or is it a case of loss leaders , or subsidy ?

Nothing to do with Irishness , or sport , or betting , but how can there be such value when the rip off mentality has been rampant for so many years ?  Pity we cant eat them !