Question about link pyramid

I have done quite research about link pyramid. I decided to try this strategy to my link building strategy for my company.

There are few still I still don't quite understand about link pyramid.

First, what is the benefit of link pyramid? Isn't simpler to build do-follow backlink to the money site instead of building them in different tiers?

Second, what keyword I should use for tier 2, tier 3 and so on. Is it any keyword will do as their purpose is to pass authority/link juice to the tier 1? Or I should focus on variation of my main keywords? Is doing random keywords break the purpose of link pyramid?

You can have a read on this article it might help you out.

http://www.penguin2.com/link-pyramid/

Is the strategy working or there are another tipes of piramids ?

What you are talking about is tier link building and yes it does work and is a good strategy. Search for MathewWoodward.
He has some interesting step by step videos on how to do this successfully.

tier linking is the way to go because you wont get slapped by algo changes. The idea is to keep "bad links" away from your money site and you do this by a tier system. you will usually want to use a 3 tier system with money site on top of course. first tier sites should be high quality links. You will want to purchase hpr domains that are expiring and fill them with good content or very well spun content. 2 tier the quality doesn't have to be as good. 3rd tier....well just hammer those with anything...thats the whole idea of tier system......