In the end the customer is paying money (or is in some other way paying you) for the value you provide and the quality of your product.
Don’t make Search Engine Optimization your core competency because it is neither what customers are coming to you for, nor is it under your control. Of course, this does not apply to people who are in the field of seo consultants.
Fundamentally, if you’re not one of the top few in your core competency, then SEO cannot save you.