There is an unusual discussion going on at Webmaster World Forums explaining what is natural in SEO and Google algorithm. According to a post, 'natural' has many meanings but has put eight meanings. Some of the meanings are:
1. existing in or formed by nature (opposed to artificial): a natural bridge.
2. based on the state of things in nature; constituted by nature: Growth is a natural process.
3. of or pertaining to nature or the universe: natural beauty.
4. of, pertaining to, or occupied with the study of natural science: conducting natural experiments.
These definitions with some rewording can describe a natural progression of a site. A natural website is that where you just put the information that your client want and do not add anything from your side. You should take all the information such as images, copy regarding the product from the clients and do not hanker to other places for the copy or images. It is your client you tell you what is the most important information, where to find it and how their customers should access the information. In short your are just an interpretor, your client knows his business the best.
Do not put thousands of pages to your website but your aim should be to attract the customers to your website. Make a homepage with a menu which have links. These pages hold lot of importance in SERPs and if some of them are indexed then it is more than good.
Make your site user friendly meaning the visitor should be able to find the concerned information by the least possible clicks, very quickly and easily. No need to build a page having thousands of links and end up giving nothing to the user. The thread gives more interesting points and you must see it.