Knowledge in war is very simple, being concerned with so few subjects, and only with their final results at that. But this does not make its application easy.You can say the same for Search. It's simple to "google" something and get the results you want. But what Google does and how it works is far from easy.
General Carl von Clausewitz
If you want to get look under the hood of how Google works, see this from Aaron Wall, author of SEO Book.