This content should be optimized for the assigned keywords. Using this method allows you to craft content themes around your keywords and this helps make these pages/sections of your site more relevant and authoritative.For more information please refer to the page http://www.seoboy.com/the-importance-of-using-silos-in-your-seo-strategy/
Technically speaking, content silo is important for every website. If you are creating content keeping your audience in mind, you never wanted to provide them information irrelevant to keywords (keyword, which brought them to your website) So, its better to create content around group of keywords.