One way often recommended to produce unique content is to take duplicate content and translate it into another language, and then translate it back into english eg English to German and back to English. The auto blogging software that I highly recommend in my free auto blogging blueprint has an auto-translate feature that does just this. However, I recommend that you DO NOT USE IT.
Why? Because, quite frankly, auto-translators do a really bad job of translating. Compound this with average content to begin with and translating multiple times (english to spanish to english), and what you end up with is barely readable garbage.
Garbage content is not good for the visitor, who you are trying to entice to click on the ads on you site. It could be argued that unreadable content would encourage the visitor to click an ad link just to get off your site, but I think it would be more likely to make the visitor go straight for the back button.
My recommendation is to use sources of good content for your auto blog sites. A better user experience is more likely to result in more clicks on ads. Worried about duplicate content penalties? You shouldn’t be. If you follow my free auto blogging blueprint the blogs WILL get clicks. I find I get plenty of adsense clicks from duplicate content, often for search terms that I didn’t expect.