Relevant in the overall big picture of landing pages perhaps, but not to the blog post at hand. That's what "Related Posts" sections are for. If you spend the time to get original content, then you should not be afraid to showcase it.

If you want break up large sections, use visual cues to break up content. Since you mentioned Unbounce, see these[1][2] as inspiration. Note the use of font size and weight, lists, whitespace and images that are directly related to the copy.

If you want more feedback, my email is in my profile.

[1]http://unbounce.com/landing-page-examples/your-landing-page-... [2]http://unbounce.com/landing-page-optimization/marketing-fail...