Autoblogging plugins import content based on keywords from various sources based on the plugin. Once the content is pulled in then it is translated several times; making the content unique. The most important part and what makes a successful autoblogs is the review of the content before posting.
Since the articles imported are translated several times from lets say from English to french to Chinese then back to English the information may have lost readability. For me I like to use autobloging plugin more as a means to fill in on the days that I am unable to post content to my blog.
My website has several articles about autobloging. http://www.autobloging.com
There are several great plugins that are available like WPRobot, Autoblog Samurai, WPTurbo, to mention just a few.
Lisa