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Lots of scarcity is fine when you can just break the currency up infinitely. If Netcoin is worth 2 Bitcoins each then everyone with Bitcoin will trade for Netcoins. This is necessary for the same reason that Bitcoin had to be 21 million so everyone with dollars would trade for Bitcoin. If Bitcoin were 1:1 with dollars why would anyone trade their dollars in? Netcoin has to be more scarce than Bitcoin for the exchange value. If it's worth exactly the same as Bitcoin why not just use Bitcoin? Even if Netcoin is better technology, if it costs a Bitcoin people will go with Bitcoin.
For me the main and most important thing about decentralized crypto currencies - besides they are the next step in evolution and the still applying early adopter bonus in the long run - is, that they
could take central banks, traditional banks and govermental ambitions out of the game. Finishing up with being lied straight into the face all the time by Bernanke, Draghi and so on.
And in this context is - IMO - enough space for several crypto currencies with different properties for different uses. Maybe Bitcoin as a wealth storage and transportation medium, PPC for serious day-by-day and investment use and FreiCoin for stubborn idealists, who are willing to pay for that.