Black Friday is about getting customers in the store to spend money. There are different tiers that retailers offer. Big discounts like TVs for half price(50% crystals), secondary level DVD players and iPads $100 off ($15 seals) then the last tier gaming consoles in bundles usually a $150 saving (pro packs 30%). That is just for electronics what they do is get u to buy the whole package and start buying other items in the store. There are always other items on discount like movies, batteries and other accessories (1.5x hte, mith increase, cheaper upgrades) these are just drivers that get the customers in the buying spirit.
suggest:
Crystals 50% off
Seals $15
Pro packs 30% off
Increase mith purchase
1.5x hte
Cheaper upgrades
This will drive your sales up and get your consumers (us) to keep purchasing from u. Once someone spends money on something they are more likely to spend again.