The Music Media Watch has an interesting feature on the impact of the soon-to-be introduced mobile number portability on the Japanese mobile music market (the general expectation is that NTT DoCoMo will see an exodus of customers).
“The bad news is that most of the larger music content companies, especially those focusing on ringtones, mastertones, etc. will likely see a drop in revenue. Nearly all of these services are subscription-based, with customers paying US$3.00 to US$6.00 each month for the right to download a certain number of ringtones within that month. As we have described in past features, approximately 60% of these subscribers are ‘sleepers’, meaning they don’t download anything, but still continue to pay the monthly subscription fee.”
However, some services will benefit..."Another likely beneficiary of MNP will be full-song music
download services, especially those run by Label Mobile. These services were strongest on KDDI (by far) to begin with, and the most popular ones are pay-per-download rather than subscription-based. Furthermore, new KDDI customers coming from NTT DoCoMo will have to buy a new handset and will likely opt for one of the many KDDI models that now support full-song downloads.”