USE CODE "BIGENT" (or if you're a Quidco user, just link directly from their website)
The above code is for purchases over £40.00, so simply add three cards to your basket, total price of £47.73, use the code which brings it down to header price, and then as a Brucie Bonus for the Quidco users, it'll track at 8%. Which brings each card to £13.41.
Of course this won't be for everyone as it's an expensive way to get cheap points, but for those who are after the "spend 2400 point promotion" this is a good way to do it me feels.
Thanks to Balajake for his maths skills (hence I altered it a bit)