Ewww.

I am guilty of using testers at cosmetics counters. I really want to know if that lip color or lip gloss looks good on me, but now I don't think I want to be doing this anymore.

Here's what I read in Women's Health Magazine

"Before you try that lip gloss at the makeup counter, consider this: One researcher found high levels of bacteria including E. coli, from fecal mater (Yes, you read right!) in samples of lipstick, eye shadow, blush, and cream taken from several different cosmetics counters. If you're getting an in-store makeover, ask for the products to be sanitized--and never put anything near your eyes, nose or mouth that hasn't been."

EWWWW.
Source: Women's Health Magazine, September 2008, p.92