Who did you build your website for? Humans, right? You want it to make sense to your prospective customers when they find it.
To much focus on creating a website that is built to be "search engine friendly" and you could forget that while search engines may bring traffic, it's still a human who is reading and consuming the content that lives on your site. If you rank well in search results but your visitors bounce off your site because it does a lousy job of showing them what they are looking for, what good is all that effort?
While this sounds obvious, it takes a certain level of focus in design to achieve the best results. Instead of just trying to create tons of content for search engine consumption, more thought should be given to the impact that content will have on the real target, your human visitor.
Think like your customer would for a minute. does all that content on your website make sense to them? Strategic placement is great - Get your Podcast on iTunes, be sure to have your video on YouTube, and make certain that Technorati knows about your blog, build link relationships all over the internet. An SEO friend of mine, Carlos DelRio wrote a book about how people using the web have caused marketers to adjust how the do business. In his book "User Driven Change," Carlos explains how the way people search has evolved as they become more adept at using the web.
For the online business, it's more than just ranking well in Search Results and driving traffic to the website, it is converting those visitors to customers. It's the human visitor that ultimately determines if your website is worth visiting, bookmarking, tagging or coming back again to see what's new. Ranking well in Search Results is wasted if it doesn't translate into an increase in business.
If your website satisfies the human visitor as the answer to their search, they will reciprocate by linking to your site, turning in to customers and telling their friends about your site. Does your website do a good job converting visitors to customers? Do you track how long people stay on your website? Do you know which pages on your site have the highest bounce rate? If you can't be found in the Search Results this really doesn't matter, but keep in mind just getting found is only half the battle.
Search Optimization will help your website get found but the Search Engines don't buy your products, people do.