An increase of relevant traffic to your site.
An increase in sales
A higher ranking on the major search engines for keywords relating to your product or service
An increase in page rank., making it easier to get link backs
More internet users know about your company and its products and services.
You are targeting your audience, only people that are looking for your service will come to your site, this helps in cutting out unwanted traffic.
Increase conversion rate
Build links and trust with other websites and search engines, expanding your reach as you do so
