Simsi - 5:28 pm on Jan 16, 2012 (gmt 0)
Personally I wouldn't pay any attention to what benefits big brand sites like Walmart as they probably have a ton of links and authority that would push them to the top anyway.
My experience is that links near the top of content have more benefit than those further down. However spreading those "lower" links around other pages instead means less links with more authority so either way, it strikes me as a balancing act and with that many links, I personally wouldn't worry either way.
Conclusion: I'd say SEO impact was minimal and I would look at the best navigational format to encourage users to hit a "goal" from where they enter the site.