Obviously a woman should feel free to write the guy if she is comfortable doing so.
I’ve just not heard many success stories of women emailing men.
The fact that the question implies that the profile is being viewed repeatedly by the same man improves her odds, without a doubt.
So why would a man not contact a woman if he is acting in a way that would suggest he is interested?
Tash has to try to keep Brett's high-profile career on track.
Brett is so bored by Tash's job, he ends up trying to make science sexy.
Even if she’s not trying to send you some type of signal, what’s one more email?
One Valentine's evening a group of single, dateless friends get together to play Trivial Pursuit.
In these cases, the woman would be less inclined to simply browse dating profiles (she already has more to deal with than she wants).
As for men, when I was dating online I knew that any woman I contacted probably had several other men contacting her at the same time.
They wake to find that each is in the other's body.