The internet likes the word free, and one of the benefits of using free content is because you don't pay for it. Yet with anything free on the internet, there comes a price, and sometimes free content may carry one all its own. There is a good thread at SEOchat describing just this and many of the members are giving feedback as to what the pro's and con's are of using this type of content.
Some are reporting that a lot of the free content isn't cracking up to be: free. One of the main problems is that people are using these articles multiple times in many different locations. I mean its free right? Why wouldn't you paste it on your site in hopes it does whats its supposed to do: Get Readers. If you didn't grab the article first or at least get it spidered first then, you may not really realize the traffic you had hoped to obtain. Personally, I don't use Free Content to publish on my sites. I either write the article myself and create all the marketing and information copy, or I hire someone to write the article for me on an area that deserves a large amount of research I don't have time for. It's actually not relatively expensive to hire a copywriter to make this happen for you. Average people (non-copywriters) can write content just as fine as one that does it professionally. I have heard stories about people hiring college students, friends, family, and those that have time to write some content on whatever subject that might interest them.
One of the members, oldmanrunner mentions that a good way to get around getting caught for duplicate content is to place "different headers, different titles and descriptions, swap a paragraph or two and change a few words" and you should be fine. Other members are reporting that they are removing many of the articles they have put on their site after the recent update, as it didn't help them. Others are saying that free content has returned substantial amount of traffic for their site.
A place that should be on your radar if you are using free content is Copyscape for checking to see how many people are using the same article, it will not however tell you whether its the article is benefical to your site. Another tool that comes highly recommend is a Similar Page Checker that compares the two articles to look for differences. You can also use something I really fond of, its the program called Beyond Compare that compares everything from articles to php documents.
Something funny, but a member asks where in the world you would get content for a site entitled "Green Squirrel Shirts". I can't say I have ever come across an article or company entitled that. Maybe you could get articles pertaining to various species of squirrels, or the benefits of wearing green squirrel shirts, or the benefits of wearing a green shirt with a squirrel on it. ;-)
Continue discussing free content on SEOchat.