I'm not sure if Liberty has rollover but their 500 minute for $20 plan blows away the $10 card as it is 30 days too. If the $10 card had like a 90 day or better expiry, it would be a different story, but the 4
cpm rate of the $20 plan is three times cheaper then the 12cpm rate of the $10 card. There's really no point to that card and the nights /weekends plan with the unlimited ...