Unless your fiat are Venezuelan Bolivares or Argentinian Pesos, I assume your local currency does not perform as bad as FUN.
No, but it does perform worse than BTC, and the key point of this investment is making profit in BTC, through premium program which requires a determined amount of FUN to be held. FUN is just the mean, not the final goal. Bitcoin is.
So, subtracting what you get from the WOF spins from the interest you won't be receiving, we have: 0.003283 - 0.001947 = 0.001336 BTC (~50 USD). So, you would need to make up that much BTC per year from the extra 1.1725% you get as a bonus. Doing the math, we get: 0.001336 / 0.011725 = 0.1139445629 BTC.
If you have at least that in your balance, then yes, purchasing the membership is a solid investment. If you do not, then you are losing money, at least in the short term. And, we have not taken into account how crappy FUN token is and the crash it has had... neither if you bought the tokens/membership when FUN was more expensive.
The investment is worthful if you aim to have a big BTC balance size to make extra daily interest. If you don't have, it's suggested to stick to maximum 12,500 FUN tokens investment tier, which is the best cost-benefit among every alternatives.
Sure, you may win a lottery prize or hit a bigger prize at times, but given the low odds, that is not likely to have a significant impact. I also assumed you get the 16 spins and the full bonus from day 0, which is not the case (but after the second year you get the full benefits, so it is not that much of a big deal either). As a longer term strategy it may work, but you will have to trust Freebitco not changing the conditions of the program and cross your fingers that nothing bad (or shady) happens to the site.
The investment reaches its full potential after the first year. I took the risk, because the site is alive and legit since 2013, plus making a solid and sustainable income offering betting services to customers. But indeed, the risk is always there...