There is a third-party risk when you keep your bitcoins on a website, a lot of us want to avoid this risk but it's interesting to consider the options to invest a portion of your bitcoins holdings and get a positive return instead of having your bitcoins just sit in the wallet.
Just-dice was trusted and successfully returned gains to investors : you could invest in the site bankroll and play against the players with a 1% edge. You had third party risk and a gambling whale could make you lose money.
As of today, freebitco pays daily 4.08% of annual interest on any BTC you keep on the website and bitfinex pays you to lend the bitcoins for traders to short bitcoins, what do you think of these two options and what other options do you know ?