The months ahead could be really exciting for eMusic now that Amazon in the US is breaking the MP3 ice having signed up three out of the four major labels wth Warner Music being the latest to come over to the non-DRM world. Better still, eMusic Christmas marketing campaign has been very successful with November’s announcement of 350,000 subscribers being overtaken by today’s news of the 400,000 mark being passed.

Presumably it comes down to deal terms now to allow eMusic to really challenge iTunes lead in the DMS market. The labels have backed Amazon, which will now doubt perform well but the better experience for music fans and the stronger editorial product is definitely eMusic. So, now, if they’re not already, the phone lines should be buzzing.