Avoid Using Frames

Frames are bad for usability and have historically been problematic for indexing by Search Engines.  Even though it is possible to find a workaround for this problem and give access to Search Engines robots to crawl a frame site they still create problems for any visitor who finds a frame based site.

If you follow the link from a search result listing to a frame based site you will land outside of the parent frameset on an orphaned document. Fundamental elements of the site like navigational links will not be present.

Some websites use hostile tactics with JavaScript or server side scripting to redirect anyone trying to load a document outside of its parent frameset to the site's home page.  Frame sites can also be easily hijacked by other websites and made to look as if they were part of the hijacker's website.