Search Engine Optimization improves your websites visibility on Search Engines, SEO is ongoing and needs to be maintained over a period of time in order to ensure a website continues to enjoy a top listing on the various search engines.
A properly optimised web site should not be considered an expense, it is a marketing investment which not only ensures that more people will visit your website it also ensures that people looking for your services or products are directed to your website. As a result you should see a improvement in the number of people visiting your site