When I signed up they soon made me a "add $2 get additional $2" offer (e-mail "A welcome gift for you").
A few days later they offered a 25% bonus (e-mail "Get Started - Make a call today").
I took advantage of the "$2 and get additional $2" offer and then the 25% bonus offer did not work. (They warned me I could only use one, as well as warning that I should use my initial free minutes before adding any credit as the initial free minutes would disappear after adding credit.)
On Christmas Eve they offered a 10% bonus (e-mail "Season's Greetings - A Gift For You!").
I wonder what they will offer next.