Any difference in international rate is determined by the terminating country. Australia is the farthest away point to call and you can easily get a rate of 5 cent per minute. On the other hand .30 to India and .70 to Vietnam are typical. The difference between the .05 rate and any other rate that is more if effectively a tax on the calls and paid by people calling from the US. In other words most of the cost of a call to these counties is not to cover the actual cost of the call it is just a way to tax Indians or Vienamese or any others who live and work here and call internationally. You will notice that many european countries and some asian coutntries DO NOT do this.
As far as the three minute rounding- this may insult your intellegence but maybe you need to think about how this works. Lets use india as an example- For $10 you can basically only give 28 minutes to India (trust me on this one, I could break it down and talk about carrier costs, printing costs, distribution, margin for the stores etc but take my word on it) OR I could offer you a 3 minute billing card that gives 30 minutes to india. Which would you buy? The only reason a product exists is because people buy it! Many people would buy the 30 minute card at the same cost if they were going to burn the card on 1 call and that is smart (2 more minutes for the same price). On average if they make two call they will lose 1.5 additional minutes so they will get 27 total. If they make 3 call they definitely would have been better off with the 1 minute billing card.
6 of one half dozen of the other for the smart consumer. The card is hoping most people don't figure it out and buy the 3 minute rounding card because of higher max delivered minutes and make a bunch of short calls thus making it profitable on the breakage. The average rate per minute works out the same with both cards.
Brian Rhodes