Lori Greiner's nickname on Shark Tank may be "the shark with a heart," but she never backs down from an opportunity to show her co-hosts who's boss.

Greiner is known for making split-second investment decisions before the other sharks have been able to ask a single question, and for being a fierce negotiator when it comes to making a deal with entrepreneurs. 

During a panel discussion in New York Tuesday at office supply giant Staples--where several of Greiner's entrepreneurs are launching products via the company's website--she shared tips for growing small businesses. Here are some edited excerpts from the discussion.  

Inc.com: Mark Cuban frequently tells contestants their companies are "just a product." Do you think you've proven that thesis wrong? 

Greiner: I don't agree with Kevin [O'Leary] and Mark [Cuban]. 'Just a product' like Drop Stop has done $12 million [in sales] in just under three years. 'Just a product' like the Scrub Daddy has done $50 million in sales. If you have one genius product and good entrepreneurs, you can turn that one product into a huge success and then of course continue to grow your business by creating other products. You don't have to stop and be a one-hit wonder. It's so much easier once you've taken one product and made it successful to then start to think of other products that can follow along in the same product line, and I recommend that.  

Inc.com: When you and Daymond John invested in scholarship app Scholly, Robert Herjavec claimed your investment was "charity." How has that company been doing?

Greiner: It was never charity. Daymond and I just laughed at that. I thought [Scholly founder Chris Gray] was a great entrepreneur and that it was a great idea. I love things that help people, so when he came in and said $100 million in scholarship money goes unused every year, I thought, 'This is fantastic.' This is a way to help people actually be able to get into school and pay for it. So for me, the decision was a quick one, and it's been doing fantastic. There are all sorts of different companies backing universities that are buying Scholly to give to all of their students. 

Inc.com: How long does it take for you to know when you want to invest in a company?

Greiner: The shortest pitch ever was actually one of my deals. It was the Heidi Ho vegan cheese. I tasted it, I loved it and I gave an offer and it was done. That was 15 minutes. But typical pitches would be an hour, and we've seen as long as two hours.

Inc.com: What do you consider to be the keys to a great pitch?

Greiner: To me, a great pitch is when the person can describe what their business or product is within two sentences, so we really get what it is quick and fast. If they have a demonstration, which most everybody does, they should do that demonstration quickly, concisely and in an exciting manner so that we get drawn in. 

Inc.com: Do you ever find ways to cut costs at your companies after you invest in them?

Greiner: Where I notice they need to trim the fat often is if they've hired a bunch of people that they don't really need. I think that's one of the biggest mistakes people make. You need to be doing the hard work yourself, and then it's very inexpensive to run your company. We have seen [companies] that have too much staff and we've seen situations where they have invested in too much inventory. You can't invest in inventory and take up warehouse space with no sales. That's going to be a real drain. I've also seen instances where entrepreneurs could run their business easier out of their home than in an office space. Today, you can really outsource a lot of the things that you need.

Inc.com: How should entrepreneurs think about hiring versus doing all the work yourself?

Greiner: I believe in running as much of the company as you can, especially in the early days, so you learn every facet of the business. Once you've learned every facet of your business, then you can be a great leader at the helm, but I believe in being knowledgable in different areas [of your company].  

Inc.com: What misconceptions do you think entrepreneurs have about being on Shark Tank?

Greiner: One misconception is that everybody will be a huge hit if they get on the show. Not everybody does fantastic the night of Shark Tank. It depends on what you're product or idea is. My company Squatty Potty had the biggest sales hands down in Shark Tank history after the night of airing. They did $1 million that first night and $3 million during the first three weeks, but some people wind up doing $50,000 or $100,000 that night. So it's not always a slam dunk.