There's a pretty good profitability tool that nicehash makes specifically for seeing if your rig will be profitable, don't forget to account for your other system power requirements like CPU, fans, HD's etc:
https://www.nicehash.com/?p=calc
According to the site at 10c per kilowatt and assuming your only using 70 watts (you will use more for powering your computer), you can make around 78c a day after electricity. You pump the wattage to a more realistic 150 Watts and your looking at about 43c a day profit, so yes, its likely profitable but you would need a few of them to make any amount of money quickly. Estimated ROI at 150 Watts is 204 days, 70 watts 146, so they will pay themselves off in the first year, assuming the 4GB continues to be enough memory to mine ethereum, if not if you use nicehash's miner it will switch to an easier coin and you may make less. That being said you'll either need powered riser to support the power, or a larger motherboard with 2-3 pcie slots, which all adds cost, however, since they'll all be running on 1 computer your losses from the computer standby electricity go down.
Yes, it will work, and yes it can be profitable.