As pointed out above, the yield per hour is currently higher for harvesting credit card bonuses than traditional stoozing with a "high yield" savings account. The problem is that CC bonus hacking is not scalable. Eventually, you've seized all the opportunities out there, made a couple grand, and then you're virtually done for 18 mos or so until the same card issuers will give you another round of bonuses.
If I was to get into stoozing, I might put the money into PFF, a preferred stock fund yielding 5.6%, rather than a 1.5% savings account or CD. PFF has low volatility, so you can currently hedge against a drop in value of more than 2.5% for half a year if you pay 1% of the value to buy put options. So 5.6% annual yield minus 2% annual hedging costs = 3.6% ROI under normal circumstances.
The worst case scenario occurs if PFF declines by 2.5% or more. Then your put option protects against additional loss of principal while you still collect enough dividends to earn your way out of that 2.5% hole and then some.
Some REITs may also be good candidates for this strategy.
The reason you might pursue this approach would be if you thought you could build credit to the point you could have, say, $100k borrowed at 0% and earning 3.6%. Then you'd have a side business earning more per year than many rent houses but with a lot less work, less risk, and none of your own capital tied up!
