While large companies often have big budgets when it comes to marketing, it's often a maze of decision makers, limited resources, priorities and laggards on the adoption curve that keep large established companies from staying current with technology and positioning themselves to take advantage of search engine optimization.

These large companies usually produce high quality content and publish it, which makes incredible link bait for product enthusiasts, discussion boards, and etailers.  This naturally cultivates links that most niche SEO professionals dream about.  The problem is they don't do the basics to take advantage of their established market position and their brand equity by creating fundamentally sound website.

These large companies really don't need to hire outside SEO firms to come in and do elaborate data feeds, link campaigns, and content.  What they do need is basic on page optimization.

1. Make sure the entire site can be crawled.  Do a site:<domain.com> and see how many pages have been indexed.  Examine the cached copy of the site to make sure the pages are properly indexed.
2. Create valid HTML and pay attention to page size.  This is simple.  If the page takes forever to load, or is broken, people and crawlers won't like it.
3. Redirects, Sessions, 404's.  Don't do anything fancy.  Use 301 redirects, make sure the 404 page actually returns a 404 response if it's a custom page.  Don't put sessions in the URL.  One url per page is the golden rule.  Session ID's screw this up, so put it in a cookie.
4. Put product names in anchor text that can be found and indexed by a crawler.

So, big companies need basic SEO to take advantage of their market position - put the basics in place, and watch it.  Once you establish a baseline and see the improvements, then consider more advanced optimization options like paid inclusion.