The answer is not so straightforward. Search engine optimization impacts your website in many different ways and SEO is a long term process that will have an impact for many months.
SEO is very effective when it comes to organic, free website traffic from search engines such as Google or Bing. SEO success is determined by a number of different factors all related to the content being indexed by the search engine's, your url's page rank and the frequency of SEO updates.
How long SEO takes to be effective very much depends on your market and competition. Market conditions and popular keywords may change quickly, which would require you to update SEO frequently in order to stay relevant. For this reason it is important that SEO initiatives are properly integrated into your content marketing strategy.
Konnect Marketing is a full-service digital marketing agency in Australia, with inbound strategies that will fit your budget. You can expect the same great results as if you had hired one of those big agencies for SEO services!