It amazes me the pavlovian dog response that hits me when I see the word "sale". Even if I'm not in the market for anything at all, I'm compelled to find out more, check out what bargain I might miss out on. Yes it's theoretically better to reward than discount - but it does get people shopping.
This little email ad from Red Balloon Days was a case in point. It's not a clothing label, nor is it even a consumer brand. It's a (mostly corporate) experiences and gift brand. So my first instinct would be to say don't use a retail marketing tool like discounting. Yet it got me to click...and I hardly think I'm the only one that will.
So perhaps taking a marketing hint from a completely different industry and trialling it isn't such a bad idea. Except for your reduced margin, using a cheap tool like email and limiting the time of the offer (eg. 24 hours) is a pretty cheap way to test an inexpensive little marketing tool.