I wrote recently about the newly-launched premium plans.
What I didn't mention is that all plans come with a 30 day free trial.
What I also didn't mention is that until 31 July 2013 everyone is entitled to a 365 day free trial (a whole year) instead of the regular 30 day free trial.
This allows you to try out any premium plan for a whole year without having to pay anything or hand over any credit or debit card details.
You can switch plans as often as you like during this time.