Shoes2468: I personally think this is heavy handed of spark to just assume they know what is best for the consumer, what they should have done was move everyone over but leave the option for them to opt out.
This is what they've been doing for a number of years - by default new customers are put on an overage plan IIRC. The key thing here is they're able to remove a piece of infrastructure which is likely costing them either via license fees or support and offering broadband how it is supposed to be provided these days (as in, no artifical speed caps).
Honestly, back when I was at Spark the amount of customers who complained their internet was unusable not realising they've gone over their cap was ridiculous. There are options for fixed income individuals still and Spark do make it easy to check how much cap you've got. Caps have grown over the years and the only customers affected would have been paying the same amount of money a few years ago for 5-10gb yet alone the 80+gb they get these days. It is just like your mobile how people have learnt to be rather diligent with watching for excess data use on their plans.
I honestly see this as a welcome change and do see the good side of it from an ISP's support perspective. Overage charges are not too expensive and are capped but the main factor here is the customer who has to understand about watching their cap and claiming ownership for excess data use - which I am afraid, there will be a few who would blame it on Spark, churn to a low cost ISP but from a business perspective these customers are low margin customers who likely make Spark around $2-5 per month in profit and are often the highest maintenance customers in terms of support need - sounds nasty but it is true.