SEO services might seem like an alien concept, especially to smaller businesses, who perhaps have not thought about taking on these kinds of roles previously. SEO is actually highly valuable to a great number of industries, and can be especially useful for small businesses in niche industries to get on the map.
Google likes to encourage more people to use their AdWords service, as it makes them lots of money. This can be a quick win in the short term for businesses, however SEO works on the longer term basis, allowing you to rank gradually higher for your specific keywords. This can be a better strategy for business, keeping you high on the search results for longer.