NBN Market report, page-23

Just remember Vocus, TPM, etc had very limited scope to target customers in HFC area's prior to NBN.

The customer would have had to opt for DSL over the HFC cable, which towards the end had much higher attainable speeds.

One thing Optus was doing in its own HFC area's was following an aggressive plan of decomissioning it's HFC Service to customers once NBN was ready.
This gave them the benefit of:
* Bringing forward the NBN transition payment.
* Reduced the marketing opportunity of other ISP's & the individuals opportunity to research/churn.
* Starts reducing Opex costs.

It's smart because lazy tax means they will likely hold onto a large portion of those customers.

Over time though there is likely to be some churn though, at the very least from:
* People moving house, the new tenant / owner won't have the prior relationship with Optus/Telstra.
* A small portion of people will always churn, seeking better deals, etc.

I'm holding out on connecting to the NBN for now, that said I'll be looking for a non-unlimited ISP when I do.