You've probably heard the words 'keywords' and 'key phrases' this is part of how you optimise your site. By ensuring your site has engaging, well written and targeted content is key (excuse the pun!) to getting traffic but that's not the only thing you should be putting effort in to!
Load times, images optimisation, tags, security and targeting are all things that make a difference towards your overall SEO scores.
Onsite SEO isn't simply creating great targeted content - it helps! - but you need more than just that, if you site is unsecured but you have a great targeted blog Google will still not rank your site highly as being unsecured is a big negative as is having a bloated slow loading site.
All these things are part of our SEO packages, managing and improving your site effectively to get the best performance.