There is no *might* about it.  Like I said, it's not possible they're paying the public fees because they'd be better off spending that money to just constantly buy coins to manipulate the market upwards instead.  You can draw no conclusion besides the fact that Poloniex is in bed with the likely single entity manipulator.

This is a big deal.  We already know the Chinese exchanges do things like this, but it's due to publicly having 0 fees open to all users.  This makes it so all markets are represented equally, just blocking out visibility of real volume stats.  Poloniex, on the other hand, has about a million different coins listed with only one single market being represented this way.  This gives the illusion to the untrained, outside observer that only one altcoin has any interest or activity and all the others are meaningless, when it's really a manufactured illusion to defraud investors.