That rant was indeed interesting. Self-promotion is certainly not something I find easy.
My sister works in sales, so promotion is what she does... and she said she just thinks of it as "communication".

But of course, to communicate something, it's usually necessary to think that there's something of worth there to communicate, particularly in comparison to everything else that could be communicated. So that's the first hurdle, and why men (as the article says) find that easier, I do not know.