4 different domains with the same exact content and structure

ok guys, good morning everyone.

here is the silly question of the day.

Just noticed some guy that i am cooperating, that he have 4 websites with exactly the same structure and exactly the same content. nothing changes, those 3 pages are mirrored.
3/4 got page rank 2 and 1/4got no page rank.
1/4 got 70k global alexa rank, so i think it is doing very well and local rank 500. other pages just over 7mill global rank.

here is my question:

is the guy that dumb to do 4 mirrored pages on 2013? or he is very smart and i am too dumb to understand what he is doing.......

maybe i am just missing something, but i think he is doomed with 4 pages which got the exact same content and structure. I think he is going to punish main site also.......

the best point is that all 4 his domains are the same, just 1 letter is changing. example: mydomain.com, rmydomain.com, emydomain.com, xmydomain.com

Does anyone know what is happening or thats just something silly and i should not bother at all?

thanx in advance for your answer.

Maybe he is just making some tests to see what will happen.
Can't you ask him by yourself what is the catch???

i understand the test thing, but would you test things on a well established site?

i think something strange is going on.........

Even with dupe content like that, often the Goog will pick one to rank and just ignore the others.

They've been getting slicker with doing stuff like leaving toolbar PR on the homepage of a site, but no visible PR for any internal pages. Might be that they're ignoring all the others and ranking the one.

Pagerank doesn't mean much anymore.

If the one site is good enough, they'll just not rank the others and let them slide. Kmart and a few other brands of that caliber have mirrors and other badly maintained junk all over the place, and ranking just fine.

A piece of advice: don't 301 the mirrors to the good site. I accidentally tanked a client site pretty bad when I found one doing the same thing.

I think you just figured out that the duplicate content penalty is a myth.