The short answer is NO.

There are many webmasters who spend a lot of time managing duplicate content, either within their site or from external sources. The fact of the matter is, the issue of duplicate content is often overly emphasized by some over-zealous webmasters. According to Google (and also in my personal experience), having duplicate content does not normally have negative effects on your site's presence in the Google index.

If you are optimizing your new web site (or page from your already established web site) for a keyword that is in high demand, you are likely to experience Google's "Sandbox". The sandbox is Google's way of keeping new web sites and pages from ranking for competitive keywords. This "seasoning" period, as it were, is Google's way of making sure you are serious about your web site before it is promoted to a higher position.

Submitting your site to web directories for SEO purposes is a tried and true way to increase your link popularity and ranking in the search engines. There are, however, some pitfalls to avoid.

Here are some tips that will prevent you from "spinning your wheels", as it were, in the directory submission game.

First of all, do not fall for offers to "submit your web site to 10 thousand web directories for only $24.