We did a website some time ago that only had a single product to sell, but you would be amazed how if doing sufficient research into your niche marketing space you can create a variety of pages that provide the information in different ways but use these various landing pages to drive the visitors down to your GOAL page.
Even with one product you want visitors to have more than a one time experience on your website.

I bet if you really sat down and thought about what you are offering you can create quite a number of unique pages of content. Plus use Social Media Marketing Tactics - there are over 1920 SMM sites out their - each one is a little soap box for you to get up on and start talking about your product, plus find other websites where you can apply some unique content that will provide good inbound links back to lower level pages in your website. Google will visit your site and will come back more often if it sees the regular addition of pages, and those pages linking to other pages via relevent links. PLUS it will look round the internet to find out if any other decent websites it gives value too is 'talking' about your website pages.

A lot of foot soldiering I know, but hey its like the Forth Rail Bridge here in Scotland, your never done painting it!!!

All the Best