Sweep,
Although it has been a while since I was active, I have heard about this type of investment. Normally, these companies will attract insured individuals who's mortality is pretty set (such as people with terminal illness). There usually is a set number of years for the anticipated death of the individual who is 'cashing' in on their life insurance.
The belief is that they might as well spend the money now, while still alive and may have a need for it. Rather morbid, but makes sense in some twisted way.
What will occur is that the individual may try to cash in the life insurance policy with the insurance company, but will only get the cash value that the policy contains. For instance, a person may have a 100k policy, but since they only had it for 5 years, it may only have 7k of cash value in it.
Depending on how soon death is anticipated, the company buying the rights to be the payee on the demise on the insured will pay a premium to the cash value to the individual. The risk is that the mortality table is incorrect at this case, and instead of the individual dying sooner, they die later.
Once the individual dies, the policy proceeds are payed to the company that purchased the rights from the deceased. The way that the rights are able to be transferred is the company is named primary beneficiary on the policy. This is done because since there is a money transefer involved, the company has a monetary interest in the individual and can be a beneficary of the person.
If I am correct in what you are describing is what I have detailed above, I am unaware of any company that has been offering 'rights' to individuals to take part in this process. The first thing that comes to my mind is this most likely is a highly illiquid investment, and I tend to shy away from the majority of those, since there is no secondary market for you to be able to sell your shares.
I do want to put as a disclaimer that I am not absolutely sure of what this investment is, and I recommend that you contact the company, research it fully and get qualified opinions from an attorney or accountant before investing in it.