In the days of prepaid SIMs and multiple phones many people carry, counting the Average Revenue Per User (ARPU) based on SIM cards has pretty much become irrelevant. I am the best example that this approach doesn't work anymore. Let's make it simple and only take a look at how I use mobile networks in a single country, Germany:
- The 'currently used prepaid SIM card' in my primary phone which has good rates for telephony and small screen mobile Internet access. Network: T-Mobile, MVNO: Congstar.
- My 'I always stay the same' prepaid SIM who's phone number is known by all my friends and via which they can reach me no matter in which country I am at the moment. When I am in Germany, I forward all incoming calls to the currently used SIM card since the price for Internet access is too high. Network: T-Mobile, MVNO: Simplytel.
- My business SIM card, the only one that is postpaid. Network: T-Mobile
- The prepaid SIM card in my car. I have a block heater which is connected to a GSM module. In the morning and evening, I call the car to switch on the heater so my windows are de-frosted and the interior is warm by the time I arrive. Network: T-Mobile, MVNO: Simplytel.
- The prepaid SIM for notebook Internet access. I can activate 200 MB for 10 euros or 5 GB for 20 euros. Network: O2/Telefonica.
- Two prepaid SIMs for notebook Internet access in Germany (€4.95 a day) or when I travel abroad and no local offer is available (€14.95 a day). Network: Vodafone. I have two so I can lend one to guests or colleagues traveling abroad.
- One prepaid SIM to use in the mobile phone abroad for small screen web browsing and mobile e-mail in countries where I don't have a local SIM card. 19 cents for 100 kB is not exactly cheap but does the job well for mobile only use. Network: E-Plus, MVNO: Alditalk.
Altogether that's 8 SIMs and 3 mobile operators. Have fun calculating the ARPU! From a technical point of view all this is quite uneccessary, one sim card for the mobile phone, one sim card for the 3G USB notebook dongle, and one for the block heater in the car is all I would need.