How does RE-Publishing on Expertscolumn Work

I Joined Expertscolumn in January 2012, a few days after I had signed on to Triond(an online writing site where you can earn by publishing your poems, articles, pictures, videos, music, etc. The earnings is not great but you can make a small amount of money!).

The sole purpose for joining Expertscolumn was for me to re-publish and earn more. And although, I have been thinking this all along...it's only now that I am taking a while to pause and ponder on How does RE-Publishing on Expertscolumn Work?

If an article is already published how does re-publishing  it really help? From my experience alone, by re-publishing on Expertscolumn I have earned double my income. And I din't have to put in too much effort to achieve this. Just cut, copy, paste from the published article to create a column on Expertscolumn. Submit! And there you have your column published(of course it is important that you follow the writing guidelines on Expertscolumn!).

It's only recently that I have begun publishing some articles exclusively from Expertscolumn. And I do spend time on Expertscolumn, nowadays, reading and posting comments, making friends, etc. In all this activity however  the question always comes up: How does RE-Publishing on Expertscolumn Work?

I mean if I re-publish here:

Doesn't it split my views? And since views generate income on Triond as well as Expertscolumn, I am wondering if there are two urls to the same article, how does it help?

A simple explanation would be, as the internet is such a vast place having your article posted on more than one site does increase your exposure. Still I am not quite sure about the details of this.

I am thinking also,

What if I post only on one site, instead of two... Since Expertscolumn is doing better perhaps I should stop publishing on Triond altogether. Then I could put in all my energy here...won't that increase my earnings too?

Confused!!!