May be it's just me that I'm not so impulsive buyer as Sachin. But here is what I do when I see the Groupon deal - ponder upon if I want to buy this or not. Of course, the % discount is always incredible, there is no question about it, so I know I'm going to get it at lot cheaper price than I usually do. But the pondering is always about - do I need it? So the moment I see a Groupon deal, I can't decide right away that I want to buy it or not. I keep pondering over it till afternoon, and most of the times I purchased the deals in the late afternoon or evening. So it takes some time for me to see the deal, and then make the decision. I can't think of myself making the decision within few minutes after I see the deal, and that too before sleep after a tiring day of work. So I actually don't mind getting these emails in the morning, when I'm fresh and ready to get started for the day. So not sure if the pattern Sachin wrote about is most common or the pattern I'm seeing is common. Yeah, that's when A/B testing will help.