Let me make it clear. SSL which mean secured socket layer is for website security while SEO is search engine optimization. They are two different thing but they work hand in hand when you are ranking non-content website. If you are selling anything online. you need it especially when you are selling it locally. Read this article. It will help you understand more: http://www.1netnews.com/ssl-seo-connection-important-search-engine-ranking/