In a recent question, I asked some questions about buffers in guitar effects loops.
One answer that I received which was interesting basically stated that I did not need a buffer for my effects send loop on my amplifier. It was also stated that Boss pedals all have an internal buffer.
My question is: in what circumstances would I want or need a buffer? There seems to be a market for them as major manufacturers build buffer pedals, but I'm looking for the actual use-case in which to use one.