If you have more then one place to publish content, such as, your blog, Linkedin, google+, etc., would it be appropriate to present the same article?
Or, is it necessary to have several different articles for each place.
In reality, you can publish the same article in most of those locations...but context is key. The audience you are publishing to within LinkedIn is going to be different than Google+; people, demographic, and mentality.
For example, you might have many cross-connections between Google+ and LinkedIn, and that's normal. It is 99.9999999999% likely you don't have the exact same audience between the two platforms. But, additionally, how you talk/share/read/communicate on LinkedIn is different than Twitter, Youtube, and your Blog.
Let's say you write a blog article about your latest fishing trip where you met an entrepreneur who taught you her 4 breakthrough changes helping her to double the size of her business. Obviously what you learned could help others, but the audience you reach on Twitter is going to be different than LinkedIn. Here's what you might do (just as basics) to differentiate with effectiveness:
Twitter post: "I KNOW you're busy but spare 6 minutes; what I learned on my recent trip will help you have breakthroughs, too. (link)"
LinkedIn post: "Hey Entrepreneurs! You'll really appreciate the advice from a successful business woman I met...while fishing. She shared her incredible success breakthroughs and I'm paying it forward - take a quick read. (link)"
The purpose above is to illustrate that you don't want to just cut and paste the same message from one platform to another. Yes, it's easy, but your audience might not understand the context behind your message. You're likely connected with business professionals on LinkedIn, while on Twitter you could have teenagers who are not entrepreneurs.