It is all about display of money/power.
You can buy the new iphone? you will show it off.
buy the black/white one and you may have to actually engage in conversation. Buy the golden one, everyone knows.
It is like buying a $30k audi A1 with a custom made $500k engine and drivetrain. If you just buy the $300k R8, everyone will know you have the disposable income. the custom A1 or a spiffed up TT though will be much more fun if you actually race it though. which is not relevant here as we are only talking about style since the phones are the same.
So, everyone only wants the golden one for the smug feeling when they take it out of their pockets. And that sells, as the article proves.
Also, any fashion study will tell you that a brand can't launch a 'thing'. Gold phones are NOT in fashion. they may be if enough influential people wants to partake in the smug feeling mentioned above. But until that happens, it is just a very temporal thing that will only last until samsung launches a golden one.