From what i can see. They give you a balance ever 144min. This adds up into your own 'pot' or 'pool'.
When you post the whole system will calculate 25% of that pool and upvote you that amount. It will thwm start to rebuild.
If you upvote when it goes auto they will give you 110% of that upvote value in that pool to build it quicker.
Hope this helps
Cool its a very fair system that in time pays