Makes sense, I stand corrected :) What I feel I can see...

Makes sense, I stand corrected

What I feel I can see happening though soon is what is happening in Perth at the moment.

The oversupply of rental properties in Perth on the back of the mining boom, as goinglong said, is causing agents to take 6-8 weeks to find a tenant.

With the housing boom, especially here in Sydney, apartments are being built everywhere. Cranes are all though the skyline
(sidenote: Sydney apparently has the 2nd most amount of cranes in its skyline in the world, behind only dubai atm http://www.theurbandeveloper.com/sydney-skyline-cranes/)

In 6-12 months time, all these apartments are going to need tenants, there won't be enough tenants to quickly fill each apartment out there.

Competition will increase, agents will want to stand out, paying extra to make that happen seems like the logical step