Sorry if it is explained somewhere, but I could not find the answer for this in the forum search function, so here goes:

How is the poll results calculated? Is it a simple add the numbers selected and divide by the quantity of votes?

If so, then it will be true that if 10 people voted on income on site A as follows:

2 people = 1

5 people = 2

3 people = 9

Then (2x1=2) + (5x2=10) + (3x9=27) = 39 / 10 = 3.9

10 people voted on income on site B as follows:

5 people = 3

6 people = 4

Then (5x3=15) + (6x4=24) = 39 / 10 = 3.9

A and B score the same, yet B's income will satisfy a higher % of contributors.