SEO is big business, as many will know. If you're selling a product in a particular niche and come on the first page of Google for that product you will inevitably make a lot of money. Working to get your product on the first page of Google is no easy feat. It takes a lot of time and effort to get it their. Some SEO campaigns might take a day to come into effect, others may take months to even years.
With UltraLinx being on Wordpress for over a year now my SEO work only really came into effect in the last 5 months. Now 40% of my traffic is from search results alone. Around 50% of my SEO efforts has been random, trying out different phrases, different words, different content...etc. Learning SEO also takes a lot of time. The way Google ranks sites keeps changing and new SEO methods always come into effect. Your SEO efforts may have worked a year ago but now they might be completely dead - it's happened to many websites. This is why SEO consultants can easily charge an average monthly retainer of around $500, it's an ever learning subject.