For the sale that just ended -
I'll be honest and say that 3 emails within 24 hours about a one-day sale is WAY to aggressive. You think that if I didn't see the one you sent in the morning that I'll see the ones sent later in the day? I got one at 4:46 AM, 11:54 AM and 4:42 PM.
Next, a one day sale is great, but for those of us working different shifts than daytime a 1-day sale is like a 6 hour sale. If I happen to get to reading your email, there isn't much time to find out if there is something I want. I just cleared my email and "must do" items and found that I was 16 minutes too late to log onto your site to *begin* to see if I wanted something.
Next time, can you try one email a day MAX and have a 2-day sale so all of us can have sufficient time to participate?