Hi everyone i have two websites named http://www.msin.in/ and http://www.achievementlabs.com/ , both website has same content , now i am want to do SEO for both sites or for one , but anyone tell me that my site will penalize due to content duplication. please give me proper advice .
Do a 301 redirect from the secondary domain to the primary domain -- this way you won't be penalized for duplicate content.
Push only one, eventually you will need to make changes as time goes by so the one you are pushing will look similar. Migrate the one you are not pushing to different provider. This way you will not be penalised otherwise it would be an easy way to compete (duplicating a competitor's site and having it punished). Change some words but keep it nice. Add to it many sub pages for links but don't call them link1 link 2, call them "interesting sites" "my friends" and so on. Don't give up on the one you are not pushing, use that for trinagular backlinks. Instead of reciprocal, you will link from the non pushed website and ask for link to your pushed one.
What do you exactly mean by penalized? Banned? As for your question no your site will not be penalized but from what i know, the page that has the original content and which was generated 1st will be on serps than the later generated pages.
I can't think of a good reason to have 2 sites with duplicate content- unless you are using one temporarilty to push to another. 2 sites with similar, high quality content, now that's a good idea!!