The magic behind any new cryptocurrency token is that since you can create money, you can set an incentive to confirm old transactions. So you can bootstrap your cryptocurrency.

When Bitcoin has no or very low subsidy, it will need a backlog of transactions to go forward. So the problem with DagCoin is bootstrapping. If you have an application where you can keep a flow of transactions going, you can make it work. Also you can add a subsidy to each transaction that has a very high PoW, and create an inflationary cryptocurrency whose price varies with electricity cost and inflates with Moore's law.