I don't recall them being given away for free; however, probably many users got them in the starting "buy one, get one free" promo. Also, for a long time, they were the biggest names in the catalogue, at least for many.
I'm probably remembering the BOGO deal then (it's been a while, burned a few brain cells in the meantime). Still, I don't think anything that was given away for free should count towards the best sellers
list. I never would have bought any of the games I got for free here and I'm sure I'm not the only one... except for Another World, I did use a GOG freebie code on that one, but I probably still would have bought it anyway.