Pre-paid data plans have recently become a viable option for 3G wireless services, and they're a good way to control your monthly costs and get broadband "on demand" rather than having to sign up for an ongoing fixed service.
However, as we've already discussed, there are some tricks to watch whern it comes to getting the best deal for your money. There are some important differences in the way some ISPs calculate the data you get when you topup your account.
On a cost-per-gigabyte basis, however, they do work out to be more expensive than monthly plans - which is offset by the fact that with pre-paid services you only pay for what you use. For example, 3 offers a 7GB monthly plan for $49. The same amount of money gets you only 4GB of pre-paid data. That's nearly 75% more expensive.
But you don't lose unused data at the end of the month with pre-paid: as long as you recharge the card once a month, unused data stays in the bank. There are also no contracts to sign and you can vary your monthly costs based on actual data use.
Also in this series, How to Get a Good Broadband Deal
Part 6: Stop paying for uploads
Part 5: Avoiding outrageous excess charges
Part 4: Bundling deals
Part 3: Beware pre-paid wireless metering
Part 2: Get a "reserve tank"
Part 1: Naked, bundled, pre-paid
You can read more about wireless plans in our Broadband Buyer's Guide: Fixed vs Mobile
Having trouble finding the right broadband plan? Try this broadband comparison service for comparing ADSL, ADSL2+, wireless, cable, naked and pre-paid plans. Another good site for comparing plans and discussing broadband is Whirlpool.