I take your point, and you're absolutely correct in that if you'd have never spent that $100 on whatever whizzy gadget you're looking at then you didn't save a penny no matter how good the sale is.
However, life is more than mere survival. If I were to buy something that I was going to get anyway then that's money saved even if it's not an immediate need. The caveat being that I hate "lightning deals" and other short time sales (damn you Musician's Friend and your Stupid Deal of the Day) because in the past I spent a lot of money that I didn't have trying to get a deal on something that I didn't take the time to properly research and wouldn't ever use.
No, no, that person has convinced me. Plus they're very handsome. You can't just come in and say things to unconvince me!