Have you heard of nomorerack? I just heard about it this week via facebook. They basically every day have new deals that are posted (noon est) time that stays live till 11:59 (est) time the next day. Unless they sell out of the deal. Many of the products they offer are 75-90% below retail price. In addition to that they have what they are calling their INSANE deals.
Nomorerack insane deals show up on the homepage in a purple box and will have things like Kindle for $15. You never know when those deals will show up you would have to be able to visit the site often at various times through out the day to catch an INSANE deal. I haven't been able to catch an insane deal, but have heard about them after the fact.
Besides checking out the site at various times the best way to catch an INSANE deal is to register with the site that way if you happen to visit the site and see an insane deal you want you don't have to waist time registering. Registration is free. You have to register with the site in order to buy anything including the insane deals. Just thought you would like to know.