An invention licensing company, or an invention marketing firm, generally refers to companies that offer an invention promoting service.
You pay them to patent, promote and license your invention.
It is not the same as an invention licensing agent, or agency, that will represent you for a commission or percentage of royalties.
The difference is that an invention licensing company will ask you to prepay funds that can accumulate to substantial amounts.
They can also be quite eccentric, very independent and definitely different.
Some inventors, like artists, may have little or no experience with commerce and lack knowledge in this field.
The lack of this experience and knowledge can have an adverse effect on inventors and on their potential for success. They can become frustrated with their progress.
They may even attempt to finance a licensing company to make their invention successful.
A singer/songwriter may pay an agency thousands of dollars to have their music recorded and promoted - in the hopes that he/she will get a recording contract.
An inventor may pay thousands of dollars to an invention licensing company to have their invention patented, prototyped and promoted - in the hopes they will get a licensing contract.
That is not how they make their profits. They profit from the funds received from their clients. There is little incentive for much else - other than getting lots of new clients.