Well, I can tell you from my experience about dealing with both...
Duplicate content on multiple websites is allowed under very strict conditions. The secret to mastering ' duplicate content ' is managing it in ' unique presentation. '
Websites: Same content, different template, different presentation, different order of listing of relevant content on the site pages.
Example:
Site A has a yellow banner with a cute kitten on it and offers articles about how-to train your cat to use a little box, etc.
Site B has a black banner with a dog with his tongue hanging out, offering the same articles and content in a different order.
Articles can be displayed on your website from anywhere, as long as they are the original, unchanged article from the directory you get them from and they are relevant to your site. They will absolutely NOT be counted as duplicate content due to any and all articles posted within a directory fall under the ' public domain ' laws of the international world, ( just like any press release or news broadcast), to used within it's original presentation format, unchanged or modified and clearly posted as the original presenter's content, AS A REFERENCE OF KEY INFORMATION to be used freely for content building of targeted information resource sites, also known as ' authority niches. '
The legality of it is in leaving the content, INCLUDING the original author information intact via links through those directory accounts. With that said, you can have as many duplicate sites as you want with the same target content as long as cosmetically, it is presented in a different presentation visually and by random navigation order to differe from the others. Proof...Every site that is powered but Mike Filsaime's butterfly marketing server is an exact duplicate, all selling his same exact ads and products with a different main product as the lead...it's duplicating the same information in a unique presentation.
Note that ALL of them rank for different keywords in the same niche so that he dominates them all. All of the ' guru ' do this. Joel Comm, John Reese, Frank Kern, Mark Flavin, RUSSELL BRUNSON...the king of cloning content...heh.
Nothing new, just not made obvious. That's my insider tip of the day, folks. Check it out and compare for yourselves...do a google search for these guys by name and read the content. It's all the same with a different package for their individual styles.
It is exactly what they teach...' The best way to mislead the enemy of your plan is to tell them exactly what you are going to do. ' They find something that makes A little bit of money and then duplicate it. This is how they got around the google slaps.
That's why I laugh when people say that web 2.0 is so outstanding, it's the same techniques that have always worked, just wrapped in a different wrapper. The ranking issue is simply mentioned above but here is a more direct check list...Pay close attention because it is going to seem too simple to be true.
1. Duplicate content in a unique presentation allows for repeat use of content you already have.
2. Articles are ' public domain ' and can be used in ANY website over and over as long as the original copy is not changed in ANY way, including the original author. You can't go reposting someone's article as your own but can post their article from an article directory they have submitted it to with a proper listing on your site.
They are bringing you traffic so give them the backlink in posting properly folks. This way your sites look completely legitimate and gain ranking. In doing this, you offer an indirect win/win because the writer will stay in business as well and keep publishing content for you to turn viral for him/her.
3. Target your duplicate pages for individual series of keywords that are alternates for each site. This will cloak your sites from being related in the search engines because they will not show up on the same keyword search page results.
Examples:
Page A- keywords; ' unique cat training ',' litter box training ',' kitten house training.'
Page B- keywords; ' unique dog training ', ' dog house breaking ',' puppy training.'
Page C- keywords; ' unique pet training ',' house training pets ', ' how-to train your pet.'
It will look as if every site is completely independent and non-duplicated to the search engines due to it looking as if it is an original content site, where you can deposit all of the same related articles and never have any of them clash.
here's a freebie for you just to prove I know what the hell I'm talking about...
Take all of those sites that you generate and do the following.
BACKLINK THEM TOGETHER!
You must do it only with your relevant content sites, of course. The way it works is that you must NEVER make the sites have reciprical backlinks..this will kill you rank.
What you must do is link them in the following order...
You have five sites:
LINKING PROCESS: Site 1 links to Site 2, Site 5.
Site 2 links to Site 3, Site 4, Site 5.
Site 3 links to Site 1, Site 4, Site 5.
Site 4 links to Site 1, Site 5.
In closing, to answer your question, yes, it is just fine to duplicate content on offsite webpages. Don't be fooled by what you see, as it isn't always what you think it is but is guaranteed to be what you person presenting the information is offering as the concept.
Hope this helps.