If you are an Agency or Web Design shop, then you are getting requests for SEO services. If you have significant business, you are getting many requests. The reason for this is simple: It works. It's no secret, people have realized that pay-per-click (PPC) advertising, while very good for some businesses, is extremely cost-prohibitive for others. These folks then turn to organic SEO as their solution for web visibility. But if your main business is PR or Web Design, SEO is foreign territory. What do you do? You outsource SEO.
The business case for outsourcing SEO is the same as any other non-essential function. As we all learned in the 90's, you should outsource anything that is not a core competency. In case you have forgotten, he's the cliff notes. Functions in your business that require time and energy but are not core to your central value proposition should be considered distractions. In most cases, there is another business around for whom that function IS core to their value proposition. If they are any good at it, they will consider that function a core competency. As such, they will have developed to a scale, quality and feature set that you will likely not achieve. You won't achieve their levels not because you can't, but because you don't want to. When something is not core, it does not get Executive attention, funding, etc. We all know this. So the business case to outsource SEO is simple, if it is not your core business, you should put the work with someone else who simply loves it to death (like us :-).
Many people get stuck here because they don't like the idea of losing control. And this where the twist comes in for SEO. There are many SEO outsourcing programs where the delivery is completely invisible to the customer. These programs, called white label SEO or Private label SEO, allow you to remain firmly in control of your customer relationship and even switch SEO vendors if things are not going well without disrupting the apple cart. In the end, this strategy allows you to outsource SEO without the usual draw-backs associated with that process.