Coinbase is targeting the US as her market base because of the believe that Americans wouldn't allow their investors to be scammed or allow any scamy ico to stay, thereby opening more patronage.
The step taken by Coinbase by targeting America as its market is right, but in the future the market of cryptocurrebcy currencies will likely move to Asia, especially Japan and China. The global market will definitely look for a very large market and that happens in Asia. must see this excellent opportunity by preparing security and technology support to anticipate the scamy ico.