It speaks about how, since most people in Cuba have roughly equal (equally low) salaries, prostitution is present in all strata of society. Example citation from the link; a prostitute speaking: "We're all on a survival plan, no matter who you are, if you're a doctor, a philosopher, a teacher, we are all pretty much the same, we make the same money,
20 or 30 cuc a month is not enough at all."