a drink at a srtrip club is not a business though. A business associate of mine was an executive chef for many years for a large hotel chain--and margins are almost even on food--the drinks put them in the black and pay the rent.
He bought a small restaurant 2 years ago (non-franchised) and has not seen black numbers regularly. But yes--re-using saturday orders for monday specials and getting folks to buy wine with dinner keeps him able to operate for now.
Internet porn? Somehow I think that fits into the definition of almost illegal or fly-by-night. Not an investment-worthy cause for me. Besides a few of the major labels, how many have been around for more than five years? Fly by night.