Why not? Depositing an amount you feel comfortable with for the 0.01% daily interest is actually not a bad idea. You will earn 1 satoshi per day for each 10 000 satoshis in your balance. Besides the daily interest, another benefit of depositing a small amount of bitcoins is that if you deposit more than 2 times your FREE BTC earnings (I remember wetsuit saying this in this forum), you won't have to solve captchas on your free rolls. You can see your FREE BTC earnings by clicking STATS and then PERSONAL STATS.
Forget about MULTIPLY BTC and just stick to FREE BTC and use reward points to boost your FREE BTC earnings from time to time or collect reward points to exchange for bitcoins, which you can do when you collect 100 000 reward points. Thus you will slowly but steadily increase your bitcoin holdings without any risk of loosing. The only risk is that you don't own the private keys of your bitcoins in FreeBitco (as in any other web wallet), so if it goes out of business or gets hacked you may loose your bitcoins. Fortunately, FreeBitco is an old and well established website with a clear business model, so I believe it will be around for many more years, but you should be aware that there's always a risk when you deposit bitcoins to a website or an exchange, so don't deposit what you can't afford to loose. Unlike most of the other web wallets FreeBitco at least compensates you to a certain degree for the risk you take by providing daily interest on your bitcoin. If you want to increase your account security you can use a strong password and activate 2 factor authentication (2FA).
+1
A calculated risk I'm willing to take, and actually taking.