what would be G's penalty for duplicate content? is it your site will be banned... or you're just going to be buried on the SERP like on the 900th position?
yes. but it can be defeated IMO. How "duplicate" is it? Exact pages? Often times if the page is 100% the same they just won't get indexed.
is your site new? usually new sites get stuck in supplemental. some ways to prevent them: unique titles, meta description, keywords, and backlinks. as you gradually increase backlinks, some of your pages (if unique enough) will go non-supplemental.
According to Matt's blog and Google's view on this subject, we shouldn't worry that much about duplicate content. The only problem is pages containing duplicated content (last indexed) will be ignored - not even listed in the 900th position!
you will penalized, very rarely completely banned for duplicate content, not really sure if thats true. If you are going to have some duplicate content on a page, atleast use a 60/40 rule, 60% unique content and then you can use 40% dupliacte. * like example, one thing amazon does, is use user reviews for unique content on each of their item pages, among some other things* although the are a very high trusted site so google would give them much more room to move when getting penalized for something, that is why I feel you should do a 60/40 rule at minimum, i like to use a 80/20 rule myself if im using some duplicate content. That should help you get past the filter. But honestly, just write unique content, read up on it, and write it better then everyone else's, it make take you longer, but its worth it in the long wrong as google loves unique content, and your visitors will like the quality information. You can try all techniques tho, I would get a hosting plan, can be either a cheap one or a dedi server, to host unlimited domains and try out all different strategies on each one, find out what works for you. Personally I create high quality sites on specific niche's with great information, pictures, etc, whatever i can think of. 5-10 pages each, maybe some pages on longtail'd keywords. Spend maybe 24 hours on actual site development, then spend like 2 weeks promoting it, and move on, I found with this stratedgy you can get anywhere from 1-15 /day each on adsense us$ dollars on these sites. I have about 50 sites so far using this strat., 10-15 pages each of great unique content on different subjects, each pull in 3-5 dollars a day on adsense on average, some as high as 10-15 a day, some as low as 1.50.. I host them all off a dedi server, but i also have many other bigger websites such as ecommerce, affiliates, tons of stuff onm this same server to offset cost more, but i use wiredtree, great stats /service and 139.99 a month is my server, although i think they have VPS for 49.99 a month. Wow I got off topic .. Oh well, i hope all my info helps everyone I just felt like tlaking about stuff on my mind, im thinking business tonight!