Lori Greiner's 4 Questions to Know Whether Your Idea Is a Hero or a Zero The serial inventor, Shark Tank star and 'Queen of QVC' shares how to figure out if you're creating a must-have product.

They don't call Lori Greiner the "Queen of QVC" for nothing. If she had a superpower, it would be inventing and selling smash-hit retail products to the masses.

She mastered the unique talent the first time she used it. During her inaugural TV appearance in 1996, the plucky Chicago native sold out in 240 seconds an earring organizer she designed. The Shark Tank star investor hasn't stopped successfully selling inventions since -- hundreds of her own and hundreds of others'. Starting with that first caboodle she made to help her mom stop losing her jewelry, Greiner has turned her eye for identifying best-sellers into a multi-million-dollar global brand.

"I may not be able to calculate profit percentages or compound interest formulas rapidly off the top of my head," she writes in her book, Invent It! Sell It! Bank It!, "but I can look at any product … and know if it's a hero or a zero."

Related: The Simple Morning Routine Shark Tank Star Kevin O'Leary Follows to Supercharge His Productivity

We recently caught up with the serial inventor (who has 120 patents to her name) on the set of Shark Tank to pick her brain for retail-product business basics and advice. Here are four questions Greiner says budding entrepreneurs need to ask themselves to know if their product idea is a "hero or a zero":

1. What is my product?

"This sounds easy, but you'd be surprised at how many people have a hard time articulating their idea," she says. "If it takes you more than one or two sentences to describe your product or business, you probably don't have a clear enough vision of how it's going to work or whom it's for."

2. Will people like it?

"We see this a lot on Shark Tank. Sometimes you have a vision and you think something's fantastic, but really nobody wants it. It's just you who thinks it's fantastic," she says. "So you need to find out if your product idea is something that people are actually really hungry for and needing, something that will be popular on a large scale.

Related: Lori Greiner Is the 'Shark' With a Heart

"Do your own guerilla market research here. Hit the streets and ask people, not just friends and family, but really go out there and find out yourself. Do your own focus groups. If people are not impressed with your product idea, tell them it's not your idea and that you're just working for a market research company. Then go home and go back to the drawing board."

3. Does it solve a problem?

"You want your product to be an answer that solves everyday issues that people struggle with," Greiner says. "Think of problems you've experienced yourself or that you've seen others experience. Would you want to use your product yourself? Be honest. Does it really solve a problem for you? Does it provide a helpful service or save work or time? If not, don't sell it."

4. Is it something people need and want?

"The idea is to create something that people can't live without once they start using it," she says. "You want your product to be seen as a must-have necessity, something that makes people feel good and that they'll still want to buy, even in hard times."

Related: 4 Simple Strategies to Turn Your Passion Into a Paycheck

Greiner points out in her book that it's the "small luxuries," such as "specialty coffees, treats, cosmetics, and haircuts" that sell well regardless of the economy because they help people feel better. "They always want to spend money on these basic things," she says. "In tough times, these are the ways we treat ourselves."