Why would I want to pay for their decentralized internet?
Haven't people heard of
I2P?
Why would anyone pay for Nxt?
Haven't people heard of Bitcoin?
Because NXT has a completely different feature set than bitcoin and is designed to be a multi-currency payment platform where Bitcoin is more suited to be a crypto-commodity.
What advantages does Maidsafe have over I2P?
Because Safecoin has a completely different feature set than I2P and is designed to be a multi-purpose P2P platform where I2P is more suited to be a commodity P2P.