[loup-vaillant]

In my experience, you have to separate 2 very different situations:

-- When I ask why I didn't got the job directly, I never get an answer. It only happened to me once, over a couple dozen interviews (I failed their silly test: debugging flow charts on paper). Even the companies who were polite enough to tell me of the rejection over email never replied when I asked why.

-- When someone else asks on my behalf (an acquaintance of the company, a recruiter, or whoever tried to sell my services when I work for a consulting company), they always get meaningful feedback.

If you're looking for a job, and keep getting rejected, try to go through recruiters. I've heard that constant pestering over the phone also works, but I never dared.