Many still get commissions or use larger conglomerates who pass on a healthy commission for international airfare. Sometimes they get special fares with the same or better conditions than the public gets for a lower price. It just depends. Not all international air fares are commissionable, but many (very many) are.
I'm glad that some airlines is making use of TAs for bookings and paying some commission.. I always thought that the airlines when switching from TA bookings, lost alot of marketing power..
One of the reasons why WS stayed in the black, while AC was wallowing in red..