We all know that SEO is critically important. People make billions of unique searches each month. So search engines drive a lot of traffic. But the content on your site must, first and foremost, be compelling (and readable) to the people who are reading it or you’re wasting your time.

Use your keywords, in context, within the text of your page. Repeat the keyword, in context, throughout the text.  But don’t simply repeat the keyword over and over again because it makes you sound like an idiot or a sufferer of some kind of obscure tourettes syndrome and it sends people running for the hills.

Many people go way too far and drop in keywords between every other sentence.

Via Line25

So, some level of keyword frequency is good, but too much is not.  The only way to tell if your repetition of keywords is super or spammy is to measure that frequency against the overall length of the content.  A keyword density greater than 5.5% could find you guilty of what’s called keyword stuffing, which tends to make Google think you’re trying to trick them.

According to Web 20 Ranker private label SEO, for best results, your content should…
•    Be roughly 500 to 1,500 words
•    Include images, titles, and well-structured paragraphs
•    Be relevant to the keywords
•    Include links to other pages within your site, or to other sites