Amaysim utilises the Optus network and offers both prepaid and postpaid no-contract deals with the same pricing model: 15 cents per minute for calls, 12 cents each for any-network Australian texts and 5 cents per megabyte for data. It's by no means the first SIM-only provider in Australia (the Everyday Mobile service from Woolworths springs to mind for starters), but the absence of a flagfall distinguishes it from most other options on the market.
Looking at our Planhacker table of call and text rates, Amaysim does come up looking pretty good. There are a handful of other Optus providers offering cheaper text rates (Boost, Crazy John's, Optus itself and Virgin), but no-one else has dumped the flagfall for calls or has a cheaper per-minute rate.
Its charges for international texts (25 cents) and MMS (49 cents) are rather more standard. Voicemail retrieval is 0.15 cents per minute -- not free but hardly excessive. The standard expiry period for credit is 90 days regardless of expenditure, which is also handy for light users.
For data rates, it's a bit less clear-cut. While 5 cents per megabyte is reasonable value in the prepaid universe, there are much better deals to be had in postpaid, as our Planhacker comparison of per-megabyte rates demonstrates. There's an option for a 30-day 1GB data pack for $9.90. Data is charged in megabyte increments. Overseas roaming charges for both calls and data are steep (2 cents per kilobyte with a minimum $1.20 charge every time you connect for data). However, that's not uncommon with prepaid plans.
For occasional users who aren't planning to use their phone overseas, the Amaysim rates may well appeal, and calculating costs is easier than with some other recent bargain offerings such as Optus Dollar Days. If you're a heavy phone user, a cap plan of some description will still likely up providing cheaper calls and data overall (as well as, potentially, a subsidised handset).
Like the sound of the Amaysim deal? Wish that option existed on a different network provider? Share your thoughts in the comments.