When the exchange rate of your currency with another (generally U.S. Dollar) has reached a point where it is at or above parity, taking into account the exchange fee which PayPal (or a credit institution) collects -- approximately 3%. This is significant when shopping online across the border.
The Canadian dollar's just dipped below PayPal parity! It's only worth $1.011 USD now.
by zeeroid August 08, 2011