You want to make sure every page is unique. Google will quickly penalize you if you copy and paste text in multiple pages.

One thing to also remember is that some blogs aren't setup properly to handle SEO, meaning that if you use a platform (Wordpress is a good example), and if you decide to add keywords to a post with a specific widget. The CMS will setup a permalink directory structure based on individual keywords. For example, if you wrote an article about a new Kids Bed you have in stock and you have keywords / tags: kids furniture, bunk beds, some blog sites will handle it like the following:

yoursite.com/blog/2010/02/kids-furniture/This-Is-The-Newest-Blog-Entry

and this:

yoursite.com/blog/2010/02/bunk-beds/This-Is-The-Newest-Blog-Entry

What its doing is creating two of the same exact page based on a keyword. A big No No.

How do you work around this?

1. Restructure your permalink directory to not have keywords in your directory, or

2. stick to only a single keyword tag, or

3. Don't use keyword tags unless you absolutely have to.

At the end of the day, do you think people are going to click on that keyword? I don't know about you, but I rarely click on them, because I know that I won't get the redefined results that I want and I'd rather type in the search box.