It's just easier to use a blog and set up your landing page within the blog. A blog gives you proper structure right from the start (categories, tags, pages) so you don't have to go through the hustle of setting it up manually on a static page.

A blog on the main page 'can' distract your viewers from the message the sales page is trying to deliver. I would use the /blog portion to gain link-juice, with the header/sidebar/footer of the blog linking to the sales page at the root.

Two ways to do this.
1. Install a blog at the root and store your sales page in the file index.html. This will 'hide' the blog's main page which is stored in index.php, with the entire site showing up in SERPs as domain.com/post1, domain.com/post2, domain.com/page1, etc. And your root page is AUTOMATICALLY linked to by wordpress.

2. Or install the blog at /blog, /wordpress, etc. and add links to the static sales page throughout the blog manually.

My preference is for option 1, though.

Thanks Nate, but the point here is to decide how best to set up a 'landing page' (or a presell page), which ideally would have very few links on it other than a buy button, affiliate link, or an email opt-in form.

He is not not to make a 'normal website', which would of course, be easily accomplished with wordpress pages.