Hi Studio33,
I used to do the same thing about a year ago. I will tell you why my strategy.
1. Most bloggers or websites that accept content only receive original content. They do not want a duplicate.
2. Google does pick up that the content is duplicate and I cannot say for sure, but I am pretty sure that the incoming link does not have any worth. I do not know this for certain.
My link building strategy
When I bought my domain (keyword domain) it had a PR2 with lots of spammy links. I bought it 2 years ago.
1. I disavowed the spammy links
2. I did directory link building, and content link building to bring it up to a PR3. I was not showing up in SERPs because my PR was so low.
3. Now that I had a PR3, anything I wrote was showing up on the first page (SERPs)
4. Now I just write articles that attract the link I actively looked for and occasionally go out and look for links. If you write about topics which people are interested in (do your keyword research) and focus on niche issues and build great content with awesome graphics, you will attract links. If you go for big concepts, it is hard to get a link. Focus on the niche. You will rank high in SERPs.
5. I will give you a specific example. We wrote an article on SEO and Parallax Scrolling since most parallax scrolling websites do not do SEO architecture. We posted the info on our blog. Note the article focuses on a very niche concept. We also had to promote the content to encourage inbound links so we went to every blog and commented about the tutorial to give it visibility. All the comments gave us a nofollow links but it did promote the material which eventually encouraged a blogger to use it in one of his articles. http://www.posicionamientowebenbuscadores.com/blog/tutorial-seo-parallax-scrolling-espanol/ - my content
inbound link - http://www.factorsim.info/2013/06/19/parallax-scrolling-en-la-narrativa-web/