Why? She may not know the difference between chicken and tuna, but Jess Simpson certainly knows the difference between making a fool of yourself singing on stage at the 3rd Annual Good ol’ Texas Pie Eatin’ Fayre and flogging a load of old tat to fans.

The 28-year-old recently revealed to Vanity Fair magazine that there’s something about Jess that’s absolutely raking it in.

“The Jessica Simpson Collection is a $400 million (Dhs1.4 billion) business,” spilled Jess of her company that includes clothes, shoes, hair extensions and cosmetics. “It’s adorable and affordable. What’s amazing right now, during this recession is that, somehow, the business keeps growing.”

Well now, we be wantin’ ourselves some of them there JS collection mom jeans...