We went into Boots (Talbot Green) yesterday... went to the check out with the 3 Cucumber Wipes (http://www.boots.com/en/Boots-Essentials-Cucumber-Wipes-25-pack_1043955) and were told that we could get 6 for £3.97.
It's not advertised, I'm assuming it's a glitch... The girl on the check out that told us said she'd found out from another store so I'm assuming this is nationwide.
Makes them 67p each instead of £2.03
Seemed like a pretty good deal to me :)