bhartzer - 2:43 pm on Oct 14, 2012 (gmt 0)
A search engine is merely a site that is a pass-thru for users, as they pass thru, on their way to another site.
A knowledge engine will tend to keep people on the site longer. If they get what they need, they will not need to go on to another site to find it.
We all know that when you keep people on your site longer, you make more money.