A few years ago it was relatively easy to position a website at the top of Google's search results.
Initially there were only few websites online and because Search Engine Optimization (SEO) was just starting, the few websites who applied the basics principles of SEO were able to achieve rapid success.
Nowadays almost everybody is familiarized with the concept of SEO and most businesses are trying to optimize their websites because the importance of being at the top of the search results would mean that they will be able to be more visible and therefore reach more prospects.