<p>This function can add extra keywords in your content, to boost its keyword
    density.</p>

<p><strong>Use extra keywords throughout the content:</strong> If you select
    this, and your desired keyword doesn't appear enough times in your content
    to satisfy all SEO factors, then the keyword will be added several times
    between paragraphs and also become optimized, untill all the SEO factors you
    have selected are satisfied. For example, it will add the term once in H1
    and once in H2, if these two factors weren't present in your content. This
    option will look more natural to the search engines, but may look odd to
    some of the visitors, because the content will be &quot;interrupted&quot; by
    the keyword a few times.</p>

<p><strong>Use extra keywords at the bottom of the content:</strong> If you
    select this, and your desired keyword doesn't appear enough times in your
    content to satisfy all SEO factors, then the keyword will be added several
    times at the bottom of the content and also become optimized, untill all the
    SEO factors you have selected are satisfied. For example, it will add the
    term once in H1 and once in H2, if these two factors weren't present in your
    content. This option will look more natural to your blog visitors, but may
    look a little odd to the search engines, because the keyword will appear at
    the bottom of the content several times.</p>

<p><strong> Don't add extra keywords in the content:</strong> If you select
    this, then the existing keywords in your content will be optimized, but no
    extra keywords will be added throughout the content. This option is probably
    the best one. It allows for a &quot;good&quot; amount of optimization, while
    avoiding &quot;overoptimization&quot; that search engines like Google have
    come to penalize.</p>