Mary Poppins is sold out at almost [if not] all weekend performances, jeez....calm down.
It's something they don't advertise...you just sort of need to go up to the box office and see if it's sold out (or check online).
Their weekday stuggles could be solved by their autumn-time switch to Wed-Sun scheduling (5 shows on the weekend instead of four. This will likely boost their numbers).
How to properly use its/it's:
Its is the possessive. It's is the contraction for it is...