The coin has blocks each minute and most of them get mined by this pool, so, i'm getting 0.158 clams aprox each day with 481 invested that means. a profit of 0.032% daily or 12% in one year.
If it so good why not many people are doing it?
because you are computing your profit in CLAMS not in bitcoin. the biggest problem with altcoins is their pump and dumps and the downtrend that they have 90% of the time. for example CLAMS got a small pump back in July and the rest of the year it has been dumping while it is worth 1/3 of what it was worth back then (from 30k to 10k satoshi). the other bigger problem is that it seems like this coin is only listed on Yobit which is the worst exchange that has ever existed!