This Emerce article explains that the non-voice/data revenue of Dutch operators in the third quarter of 2006 amounted to 226 million. This compares to 199 million euro in the second quarter. Meaning that in 2005 a total sum of on average 800 million euro non-voice services are being paid via mobile phone. Even when assuming that half of this market is paid by pre-paid clients, the e-money market via mobile can be estimated to be at least 400 million euro.
This is quite a significant market to leave unregulated (which is actually the plan of the Commission, on the basis of the argument that a huge number of small payments do not require regulation given the small individual size of the payments...).