Old were those days when a single page website could get higher rank in Google Search. Even I had experienced that. I had one page blog where I put just a simple article which was fashion related and after a month I was getting some good traffic and Google had assigned it PR2. But now such miracles are the dreams only. Now the only thing that matter is authority. An authority website can do miracles even if the content is not that much good. The examples are before you like Facebook, Blogspot, Google Plus, Twitter, Linkedin, Hubpages etc. Anything posted here not only gets indexed instantly but appears high in search results as well. No matter how bad is the content, how badly written it is but when you see the Google search results, you see mostly the links from authority websites. So lets make your website an authority website.
There are several ways which makes your website an authority website. The best is to get good quality back links from authority websites but due to high demand getting back links have become an expensive idea. What else you can do it to increase the number of pages of your website. Total Number of Pages effect your site SEO to certain extent. The concept gained some weight about a couple of years ago when Google was asking for nothing else but content, content and content. Someone invented a formula that Google pays good attention to blogs and websites having at least 100 pages. There are several reason behind believing in the supposition that total number of pages effect your site SEO.
If your blog or website is about some specific topic or keyword then have more pages gives an impression that you have more research and more information about that specific topic. Search engines starts showing your website in the search results as it feels you have more information for the user and his hunger will get satisfied here.
When you have a keyword specific blog or website with many pages, you often use long tail keywords. Each long tail keyword as some target audience and which starts giving your some traffic which gives a strong impression to the search engine like Google and Bing that this specific website or blog covers all the areas of that topic and hence it starts considering about your website and start showing it higher in search results.
Your website gains authority even if you have a versatile website covering lots of different topics but have lots of pages as well. When you pages starts getting indexed, you start getting visitors of different interests. There are more chances that a user came for some specific information may also like other topics or articles on your website and hence the user engagement goes up. It creates a good impact and search engines feels that the site is satisfying the need of the user. As a result it gives your website some authority and you start getting more traffic from search engines.
Keeping in view the discussed reasons we can say that total number of pages effect your site SEO. But here one thing must be noticed that to reach that level, the content should be quality content, properly formatted which keeps the user engaged.