according to Avril - the venues are sometimes HUGE , say 20,000 people can go to them, but there are only 10,000 tickets on sale. So it looks like she isnt filling the Venue , but she isn't intending to. I dunno i read that somewhere so i believe her- it makes sence
Funny that she apparently isnt selling tickets when her MOntreal concert was #10 in the most grossing concerts of the week!!
Hope this helps