Are there certain industries that utilize SEO the most? I know that any company that relies heavily on their website for sales or interaction with customers will greatly benefit from SEO, but are there specific industries that seek SEO expertise a lot?
SEO is not industry specific. A business in any industry looking for local, national or global business through their website can go for SEO for online presence and promotion.
Any business that has a business model centered around online customers can use SEO... Now I think SEO might slowly move on to SEM... So it's more of the interaction and response rather than the link building
I have done on major level the products like - mobile phones, online games, furniture stores, tours & travels and few section of servces like transportation / courier.
Today world is shrinking specially because of fast development of Communication modes. Today there are Internet is used throughout the world and every industry wants Web exposure to generate maximum business. Therefore it is not specific which particular industry needs SEO, it is the need of everyone who wants to grow through Web World.
Every industry or business that wants to get leads from the worldwide & increase their business globally, needs the SEO.