i cant say for sure. but as the free coins are given as Steam Power, which vest over a period of 2 years.
it will be very time consuming to cash these out over two years.
so i would think that the fraud potential is low on the signup side. i dont know about the voting site , there might be some fraud potential
Yeah the 2 years period is a good idea.
Also voting power minimizes the effect of fraud in voting.
yeah, the concept is good.
there will always be fraud, if money is involved. but i am sure someone will come up with a fraud dectection tool and earn a lot of money ;)