A very good back and forth at cre8asite is currently underway. The thread starts with a gaze into the crystal ball of SEO and looking ahead to the future, but it evolves into a debate about the definition of SEO and whether aspects like usability, conversion rates, site stickiness and others fall into the realm of SEO. Some strict definitions come from Randall McCarley:

SEO at it's basic level just makes a site receptive to the SEs. It doesn't have as much to do with ranking as indexing. Getting better SERPs is often considered SEO but really when you are doing things out of the Guidelines, like getting BLs, you aren't letting the site stand on its own merits and that is manipulation. Don't get me wrong - I don't think there is anything wrong with it. I do think it's beyond the intention of SEO.

Mano70 agrees:

SEO hasn't anything to do with humans, and that's why the SEO-word should be buried in the context people are trying to use it now. The SEO word doesn't cover

  • accessibility for humans
  • usability for humans
  • readability (writing keyword rich texts can be about readability, but not in the name of SEO)
  • making semantic websites
  • making a website that converts into sale (if that is the purpose)

The only thing the SEO-word covers is Search Engine Optimization (better ranking), and that has nothing to do with humans.

And Nadir thinks that SEO is too narrow a term to define the services:

So for those who are saying that SEO is usability, web design etc... don't underestimate yourself: call yourself Internet Marketer! SEO is just one part, it can work by itself, sure, but adding a few components to it make your job easier and allow you to get a better ROI, a better brand awareness and so on.

I'm aligned against these singular definitions, not just because I believe in the value of more wholistic SEO, but because I think the fundamental heart of optimization is higher rankings, and therefore, anything attempted to that end fits into the scope of SEO. In my mind, every one of the following is a natural component of SEO and cannot be separated:

  • Usability
  • Design
  • Coding
  • Accessibility
  • Information Architecture
  • Content Creation
  • Public Relations (on and offline)
  • Advertising (on and offline, as long as its directly intended to benefit the website)
  • Social Networking

Literally anything and everything that would help the site build links or attain higher rankings fits under SEO. It's also my opinion that as one moves up the consulting chain in this industry, these aspects fit more and more into the expectations of clients.