SEO is great, but it's definitely not needed by all types of businesses, particularly those who are not prepared for playing the long game that search engine optimization involves. It can easily take 6 months or more to move up in the rankings for Google, Bing, Yahoo, and other search engines.
PPC (pay-per-click) from Adwords, Facebook, or elsewhere is also a great solution to drive targeted traffic, but it's a short term fix. That's why I've advocated combining the two for many of my clients.
Here's a compelling argument from Tyler Thursby at Search Engine Journal why it makes sense to consider PPC & SEO side by side:
How to Dominate in Search Marketing: The Case for Combining PPC & SEO by @tthursb
Organic or paid search — they’re fundamentally different yet two sides of the same coin. Having tunnel vision for SEO or PPC doesn’t make much sense when they both help you get to where you want to go. What binds the two strategies together is their purpose: increasing visibility.
Source: How to Dominate in Search Marketing: The Case for Combining PPC & SEO by @tthursb