You can buy a 10, 20, 50 $ card and put it in your phone, if you finish the card w/i the month buy another one if not then the money you didn't use will go over to the next month...
There are also deals such as incoming free, evenings and weekends, etc. For more information about these deals call 1800ROGERS1...
All the features (e.g. caller id, voice mail is free)...