Payouts are completed daily.
Daily devidents for 1 unit are calculated on (total earning - maintenance fee) from product divided by number of total units.
Maintenance fee is converted to BTC on payout calculation based on the current exchange rate from crypto.bg
There is no contract expiration. You will receive daily devidents until profit from mining is greeter than zero. If a cloud product dividend reaches zero for more than 7 days, product is terminated.
Many factors come into play such as bitcoin price, network difficulty, etc.