I had to do a presentation to a couple of hundred business owners the other day, of which only a handful knew much about search and I wanted to explain the complexity of search engine algorithms and the importance of linking strategies. So anyway, based around real world social linking theory I think I have worked out a simplest analogy the audience can understand:

links = love

Here's one of my diagrams.

• Everybody likes to be loved
• No love is not a good thing
• Cheap love is bad