Free urine

For the Mandarin illiterates out there, the signs read (direct translation)

Top: "Every one (每位) collect fee (收费) 30 cents (3角)"

Bottom: "Gentlemen (男士) urine (小便) free (免费)" <-- ok, this translation is unintentionally funny

I wonder, why guys can use the washroom for free? Is it because they don't need to flush? Or use the toilet paper? Or wash their hands?

Or the simple fact that lady's urine are more precious than men's?

I knew we were a special breed all along!

**Picture courtesy of my dad, taken in Shanghai of course.