They just randomly gave varying amounts of Cartel Coins on the ptr for people to test the Cartel Store. On the live server, you are granted a total amount for how long you subscribed with various other complimentary amounts depending on if you had an authenticator for the game, whether you purchased the Collector's Edition or Digital upgrade of the game, etc. That total is not a per character total either, it's per account. Each of your characters can use coins from that total but whatever amount you use on each character is deducted from that total. There is a thread a couple of spaces down from the current thread entitled "Check out how many Cartel Coins you may receive!" that has a link to see how many coins you were going to get but at the time I posted that the list apparently wasn't complete as I received more than it said I was going to get there. Subscribers are also going to get coins added to their account each month. The base amount I believe is 500 but there are a couple of instances where you could get more than that per month.