If btc slumps then you are making double profit (from interest and from stable pegged $ value) for sure?
It's all a matter of risk-adjusted profit. If we suppose BTC will reach $675 (high point of 2014 Apri) in 45 days with 30% confidence, then it is 15% gain in 45 days at 30% probability. An equal risk-adjusted-park-rate would be 4.5% in 45 days. The offered 2.77% is not bad at all considering that you might not be able to sell at the high point of trading, your btc won't be in your hand when trading ...
Yeah i understand i guess it seems not bad if there is liquidity.