Stupid Noob Question

Hi,
I just want to ask, duplicate content affect SEO right? Then autoblog use duplicate content. Then why SE will ranking autoblog higher than the original blog (in some case)? I'm now confuse either want to change my blog to autoblog or not. Because my blog now only has average 3-5 UV per day. So I'm thinking to make it autoblog. Is it ok? Just asking for opinion.

Google has said, openly (take it for what you want), that there isn't a "duplicate content penalty" per say. But, if they see a bunch of sites with the same content - rather than ranking them all, they often pick which page(s) are the most relevant (IE posted content first, most trustrank or has the most links) and de-index the rest. So with that being said, unless you plan to outlink your competitors or the original authors of the work - you'd be better off rewriting the content. If anything, rewrite it so you don't get slammed with DMCA complaints.

Ok. I got it. Thanks a lot.

One more thing, is it can affect my SERP for displayong duplicate content?before this I use original content.