Just to add (as loads has been said by so many what I wanted to say
):
It's believed that H&M were not paid by Oprah for the interview.
It is, however, not known whether they'll get money for rights sold (and whatever else brings in money and might get them a cut, like ads).
This is part of their brand building and upping future fees.
I don't get why there's a million articles about this interview and such a discussion everywhere, all we've seen are Oprah's sound bites, added visuals of Meg (which could be from any point of the interview, not even an actual reaction to Oprah's soundbite) and a little bit of what Harry said, which is nothing new.
I can't imagine the avalanche once this thing's aired by the rate everyone's going from this nothingness