Keep in mind when a company says they have "interest" in your idea/product that does not mean go out and buy a new car, plan your Hawaiian vacation or quit your job. It means they are going to take a harder look at your idea/product and do their due diligence to see if your idea/product makes sense for them to consider for their product line.
A lot of things still have to fall in place for you to move to the next step of negotiating a licensing contract. If all you had to do was get interest I would have about 45 products on the market right now. It is fine to get excited that you found a company that sees value in your idea/product and wants to take a closer look. Just don't let that emotion make you do something that can harm you financially.
Companies will want the chance to gather information on a new product they are interested in along with estimating the cost per unit, molds, and (ROI) return on investment. Some will want to show it to buyers to gain interest so they can gauge potential sales. They may want to do a focus group and a myriad of other tests.
So, when a company says they have interest you are just starting to get the ball rolling. I have seen a number of Inventors post online that company X is interested in their idea/product only to have that interest quickly fade once they got further into their due diligence.
Also seen interest drop when the company found out the Inventor was all over the internet posting about their companies interest without their permission. Inventors forget companies like to have any advantage possible when they release a new product on the market. Having an Inventor telling about the new product can give their competition time to develop their own product to compete with the new one, which cuts into their sales. And if the other companies’ product is better than what the first company planned to release it can kill the first one before it even gets on store shelves.
I tell Inventors to hold off the excitement until they receive that first royalty check and it clears the bank.