*buying power as an assumption that you could buy the same things with external gold.
Tying currency to a physical substance (gold) only makes it easier for outside organizations to manipulate that currency since they can play with the values and availability of stockpiles of said substance outside of your control. Granted, this can of course still occur with an abstract currency (dollar) but its a lot harder to do so.
I'd rather my currency not change in value more an investment in penny stocks. Maybe it will smooth out once the final blocks are mined out but I won't be holding my breath.
I assure you, it's a real site. You may want to check for malware.