I send the email, then post immediately after that I sent an email as a courtesy to Yangdu and any other interested buyers. I appreciate it when others post that they've sent an email too. As far as I know this isn't a rule but I believe that it's helpful to others more often than not.
The system is not perfect. Occasionally several people will wind up "racing" on a particular item for a variety of reasons. Sometimes Yangdu has more than one and everyone wins. Other times, not.
Some mail servers are faster than others. I've been told that email from one AOL user to another is essentially instantaneous, giving AOLers an advantage over the rest of us. Fine with me.
The chitchat? I just scroll through, looking for "email placed on" and "xxxx is gone." It only takes a moment and when I get to the bottom and I haven't seen anything saying that my next perfect khukuri is gone, I consider that a go-ahead to send an email. If it is gone...well, maybe I'll get the next one.
When I first got here folks explained to me that my khukuris would find me and not vice versa. It took me a while to realize the truth of this. There have been numerous instances where I
just missed my dream purchase, only to have one literally fall in front of me later.
I believe that the path is more fun than the destination sometimes. Regardless, Yangdu is doing us a real favor with these DOTD's and I'll support her efforts, however she feels like doing it.
Those prices on the website ain't half bad either...

(Finally sprung for a 22" GRS, if anyone's curious. Let's hope this one's not after my fingers.)
Lest we forget, it's worth checking the Knife Exchange here occasionally. I've scored a few of my favorites (chiruwa YCS, hasiya, antler handled KK, villager WWII) there, all at discounted prices.
Honestly, though? I like the chaos and luck involved with the present DOTD's. Sometimes it's nice not to have to wait in line, you know?