Think of it this way: What do you have more chance of hitting, a distant, tiny target or the broad side of a barn? For the sake of search engine optimization, you want your website to be the broad side of barn. The more quality articles, or unique readable content, your website or blog offers to search engines (and therefore the general public) the more exposure your website will receive from major search engines.
There are a wide range of applications that might benefit from the content rewriting capabilities of ArticleRewriterTool. The obvious applications include building content for your website or blog. Other applications include any kind of essay or creative writing (virtual or not), twitter, newsfeeds, Craigslist posts or even paid article writing services.