What Is Litigation Finance and How Does it Work?

I’m researching litigation finance – AKA legal financing, settlement funding, third-party funding, etc.: the practice of investors funding lawsuits in exchange for a share of the ultimate damages or settlements. I think this is a fascinating topic: I’m looking for experts on this topic to speak to me about the history of this activity, who’s doing it, the pros and the cons it entails, what’s right or wrong with it, how fast it’s growing, what typical returns are, etc.