SEO can be more successful than a single marketing employee at a fraction of the cost. Why? You get a team of experts who guarantees their results and doesn't require medical, 401K matching, vacation days, sick days, a parking spot or any other equipment—all for around $30K/year. A marketing employee however requires all of those things, doesn't guarantee their results and will have a base salary of $60K, not including social security and everything else. That makes it pretty clear what the most cost-effective solution is.