NMC, as it is popularly called, has tons of advantages. It is censorship-resistant, allows you securely transfer arbitrary names (keys) and attach values (data up to 520 bytes) to the keys as a user, has its transactions confirmed in a separate blockchain database, and so much more.
While it is a cryptocurrency that functions much like Bitcoin, the truth is that NameCoins themselves were not designed to be used as currencies. However, this is part of the reason it is unique today. It serves both as a virtual currency system and also a domain registration system. To enjoy the wonderful benefits of Namecoin, you first need to have a safe and secure Namecoin wallet with which you can trade with.
Also, see: Top 5 Best Namecoin (NMC) Wallet Reviewed