i don't know about the world cup effect.. but when I bought an expensive 37" tv, a stand, a ps3 and a couple of cheapo cables (2x hdmi cables for €15) in harvey norman.
They gave a huge discount on the stand (it was effectively free), and a good discount on the tv. They could not give a discount on the ps3 because it was essentially fixed price, so processed a further discount on the tv.
I took with me a copy of a "deal" I was supposedly interested in in Currys. I didn't like currys. their stands were out of stock, and they tried to flog me a €65 gold plated hdmi cable and €50 gold scart lead - but as part of their deal giving me a discount of €10 on each.