jrbnz

Firefox doesn't seem able to connect to a specific open profile and make a new window, if you run Firefox without --no-remote, it always opens a new window for the oldest instance, which makes keeping multiple profiles open a pain. If you close your browsing profile while your have your email profile still open, now the Firefox icon will open windows in your email profile.

If you make an icon for your various profiles that uses '--no-remote', you can only open one window with that icon. To open more you'll have to find the running instance.

I generally prefer Firefox so if I've missed something I'd love to know, but I searched high and low for a solution and in the end I gave up and swapped to Chrome. Now I have launchers for Facebook, etc. that behave exactly as you would expect. You click the Facebook icon and you get a Facebook window, running the Facebook profile.

I thought the same so looked for the original article on Google Scholar. From Fehr and Gachter, "Altruistic Punishment in Humans":

... groups with four members played the following public goods game. Each member received an endowment of 20 money units (MUs) and each one could contribute between 0 and 20 MUs to a group project. Subjects could keep the money that they did not contribute to the project. For every MU invested in the project, each of the four group members, that is, also those who invested little or nothing, earned 0.4 MUs. Thus, the investor's return from investing one additional MU in the project was 0.4 MUs, whereas the group return was 1.6 MUs.

Your return on an investment of 1U is 0.4U, so it's always best for you personally to keep a unit. But the group return is 1.6U so the group as a whole is enriched for every unit invested.