Muhammad Shahid Nazir is the online sensation behind One Pound Fish. (Screengrab)

A fishmonger. A song to draw in customers. A cellphone camera. And another viral video sensation. It's going to be the next Gangnam Style!

Exactly what the world needs, hey?

And yet unlike Korean rapper Psy's inescapable earworm - which hit the unprecedented one billion views mark on YouTube - One Pound Fish already has a whiff of day-old seafood. It shows that for better or for worse, Gangnam Style was lightning in a bottle, and most viral video stars still measure their fleeting fame in weeks.

For the blissfully ignorant, One Pound Fish (or £1 Fish) began as a viral video that started to gain traction last summer, featuring London fishmonger Muhammad Shahid Nazir performing a song to lure customers to his stall in the city's east end. "Come on ladies, come on ladies, one pound fish!"