Many times the pub owner chooses someone knowing the person leading will draw other musicians. A friend of mine runs sessions probably at least 5 nights a week at various bars. He's there all the time & he's the draw for other musicians & customers alike & he gets paid & well he should, even still, depending on the bar the drinks may still be half priced or food put out for the players. I don't know how it is in other areas but in the Boston area Irish bars open at an extreme rate & one of the ways to start a draw is with a session. Barry