Board Thread:Game Discussion/@comment-11710472-20130721110956/@comment-10822880-20130723061630

Again trading sounds simple, but will be virtually impossible in practice. There is no benefit for Mobage in your system as you can earn points for free, so therefore trade for free (I have a surplus of 15 million points). Secondly the sell value is far less than the value of the card; a level 4 card would need to worth at least 10 times the sell price (probably more) otherwise I'd just sell it rather than waiting around to increase my points tally by 0.0001% when a match is made.

For Mobage to develop at trade system it needs to be a) hack-proof and b) profitable. I don't think it is possible - they might as well just sell cards themselves