HOW DOES THE POKER SITE DECIDE ON THE RAKE?

THIS IS THE RAKE FROM A HIGH LIMIT TABLE
$2000/$4000 - Limit Omaha H/L
*** SUMMARY ***
Total pot $36,000 | Rake $1
------------------------------------------------------------------------
THIS IS THE RAKE FROM A MID LIMIT TABLE
$200/$400 - Pot Limit Omaha Hi
*** SUMMARY ***
Total pot $4,200 | Rake $3
--------------------------------------------------------------------------
THIS IS THE RAKE FROM A LOW LIMIT TABLE
$0.05/$0.10 - No Limit Hold'em
*** SUMMARY ***
Total pot $4.05 | Rake $0.40

I'm not sure. At first I was thought it was determined by the total pot, but then the $3 rake was from a smaller overall pot than the $1. Maybe it has to do something with whether the game is limit or no-limit, but I am not sure about it.

Note 1: Moving this to the correct forum.
Note 2: Please stop posting in all CAPS. It is unnecessary, considered yelling, and against forum rules.

Anyway, the rake from any particular pot is governed by the rules published by the poker site. You need to see each site's individual rules as they do vary. But as far as how much they will take as published in their rules, they decided that internally based on what they feel will maximize their profit and what market will bear.