Here’s what a recent Spam email had to say about on-page Search Engine Optimisation (keyword also goes here):
First your keyword must appear in the title.Then it must appear in the URL. You have to optimize your keyword and make sure that it has a nice keyword density of 3-5% in your article with relevant LSI (Latent Semantic Indexing). Then you should spread all H1, H2, H3 tags in your article. Your keyword should appear in your first paragraph and in the last sentence of the page. You should have relevant usage of bold and italics of your keyword. There should be one internal link to a page on your blog and you should have one image with an alt tag that has your keyword.
Assuming their keyword is the word “keyword” then they have achieved 5% keyword density. But since the keyword for this post is also “keyword” Google is by now shaking its little botnet head and sending this to SEO purgatory.
Our advice would be to keep on-page SEO in mind but not at the expense of readability. And remember the last sentence should contain the keyword.