5% Coverage - How much ink will that do?

We all what to know how many pages we can print with our inkjet and laser cartridges, and it's very exciting to think we have it figured out when we by a new one, check the box and see the word "yield".  Frustrated, thinking you are going to get 400 pages using your new purchase and only got 150 pages instead you look at the box again and ask what the heck is 5% coverage?
We have searched for a link that shows examples what 5% 30% etc coverage really looks like:.  http://www.preton.net/pagecoverage.htm