CLAM has gone from $0.82 to $8.85 in a year. Add to that what you would have made in CLAM by investing them on Just Dice. Obviously that 0.82 to 8.85 return isn't sustainable.
In my calculations I'm assuming that the market cap in USD stays stable, and that profits come from staking more than you "should" (thanks to most CLAM not being used to stake) and from gamblers's losses at the casino. If you also consider that the market cap is going to increase, then investing in Just Dice is even better.
The exchange rates have risen just because of the hoarding by Just-Dice. When they face a financial emergency and decides to dump the coins, the prices will crash by 90% or more. I have checked the price patterns of CLAM. And it looks like a currency for which the prices have been artificially inflated, by keeping only a limited portion in free-float.