Honestly, my first piece of advice would be to read my book, Throwing Rocks at the Google Bus. It’s the most concise I was able to make the answer to the exact question you are asking.
I realize that’s a copout on a certain level, but it just takes a few hours to explain this. I put plenty of ideas in the book, but more importantly, by spending time with the new model and seeing it explained in a number of contexts, it gives you the ability to apply the model yourself to your own situation.
If you read it, I would be happy to answer any questions if you still have them, though.