Expertpeon alluded to this in another thread and I can confirm in a weight loss related niche with a kw that has over 200K searches p/month a top 5 result is had with mostly Russian footer links but they are not sitewide links.
I've been trying to figure out which niche you are referring to, pretty sure I know which one. If so, get out of my niche (been a major player there for awhile)

200k searchers/mth ... not too many niches that large. The site in question is actually NOT making $20k/day... my guess is <2000/day (since it's an affiliate site if you're talking about what I think you are). This site did NOT survive penguin, rather, they didn't start it until after penguin. So maybe I'm wrong about the niche (the site in this niche was #1 like 2 weeks ago, so maybe you're talkin about a diff one).
I've had 4-5 sites rank #1-#3 in this niche's major terms in the last year for periods ranging from 1-3 months and I know precisely how many sales/day etc occurs at the top. Affiliates tend to do a whole lot worse than stand alone brands. These sites will last a month or so, which will generate 60-100k or so for them. A good amount, but not 7 figures. With a stand alone brand, zero affiliate costs, no overhead etc, you'd need ~10-11 months across 3 related keywords to make 7 figures in that niche (been there, done that). CPA in that niche maxes out at around $10/sale (maybe $20 if you choose one company, which is VERY pricey and most people won't buy there).
I've seen a LOT of sites lately ranking via these footers, which previously didn't work too well (thanks Penguin 10/7?)
I know of 7 major (MAJOR) weight loss niches with them in the top 5 as of yesterday afternoon. I do not market in all of those niches, just things I've seen.
I can only assume a lot of other niches are overrun with them at this point.
We may simply be witnessing the redirection trick that worked for a period of about 2 months after Penguin 1.0, but this time it's with footer farms. These sorts of things have been historically poor, but are working now perhaps for a brief period of time.
By the way, in all cases, they have no other links besides these footers from russian sites.