The squidoo stats shows you how many visits you have had for the last 7 days. If you have a lens that has had 0 visits for the last week, then something isn't right on that lens. It is time to go back and take a big look at the intro text and title, the main title for the lens, and your 3 word key phrase. Are you targeting a key phrase that has to much competition? Try to narrow your key phrase down more. When you write out the introduction module text, use your key phrase at least three times. Here is a good example... 2010 Ford Mustang Also, use your 3 word keyphrase in the titles of several of your modules, and use it in the text of those modules.
You want to add fresh content to your lenses at least on a monthly basis. More often than that if possible.