Are fees necessary for clam? If staking is same and not ending over the time ?
I believe so - it seems to be 0.0001 CLAM per kilobyte or part kilobyte of transaction.
The reward is 1 CLAM per block, and the target is 1 block per minute.
Note however that the protocol has changed several times. Initially the reward and the chance of staking depended on the age of the output being staked. Later the reward changed to a 'lottery' based system, where the reward was 0.1 CLAM most of the time, but up to 1000 CLAM for rare winning blocks, but old outputs still staked more easily than new ones. And later again it changed to a flat system where every block staked earns the staker 1 CLAM, and the age no longer matters.
Also sometimes, on Just Dice i shows 2 CLAMS staked. Since the reward is 1, then how does Just Dice claim 2 sometimes?
Just-dice reports on the stakes once a minute. So if it had 2 or 3 or even 4 stakes in a 60 second time frame it reports that it staked 2,3 or 4 clams. It's still only one per stake, but they hit multiple stakes. The average target is 1 per minute, but you could get 2 one minute then nothing for 2 minutes.
