Simple Factory pattern versus Factory Method

Hello,

Here's a good url describing the difference between different factory pattern implementations:

http://corey.quickshiftconsulting.com/blog/first-post

I think the "simple factory" described  in the article may be the pattern that developers most commonly implement as a factory pattern.

The "factory method" pattern seems to add an additional layer of complexity but I'm not clear on how this additional layer of complexity adds value over the "simple factory" pattern.

Can someone here articulate how the additional layer of complexity of a factory method pattern over a simple factory pattern adds value and in what scenarios you would justify the additional complexity of a factory method over a simple factory?  What are the benefits?

Also, would you say that a simple factory pattern would be a more appropriate choice for most real world biz app dev scenarios?