The duplication of a large portion of a web page's content on another website or page will be considered spammy by the search engines and therefore should be avoided.
The majority of search engines run a duplicate content filter on the data collected from websites. If the content of two pages appear too similar, the search engines will penalise one or both of them. Usually the site that was seen to have the content available first will retain it's ranking.
The same rule applies to pages with similar content within a single domain.