Perhaps I should say that the theoretical ideal for any altcoin is that the largest possible community gets involved with the highest possible market cap gain (for their efforts) with the lowest possible risk, thereby maximizing risk vs. reward.  There are funds on the stock market that err heavily on the side of lowest possible risk, rather than being get-rich-quick options.  In my mind, this would be a better altcoin option (for those who want or need greater stability for some part of their portfolio).  Money market funds, stable value funds, treasuries, and municipal bonds tend to offer poorer returns, but manage a large market cap anyway, because there is less chance that such diversified funds will decline.

Accomplishing the same with an altcoin, in my mind, means gaining maximum growth through CPU mining (since everyone has a CPU, and there are various barriers in place to buying altcoins with the cash in your pocket).  Developing a wide index of prices (precious and semi-precious metals, international price indices, etc) would be the difficult part.  Reading in those values each day to determine if and how much demand exists for reward coins is less difficult.  New altcoins are less known, are accepted by fewer vendors, and will be seen on fewer exchanges.  Early adopters need a real incentive to download the wallet and CPU-mine, but that increase can decline as such an altcoin becomes more widely used.