How many of telco subscriber numbers are 'real'?

Mobile operators in Singapore offer discounts to subscribers who sign up for multiple mobile lines, but how many of these then are active lines?

I was at my mobile operator's service center over the weekend to purchase a new phone and recontract my mobile plan to one that includes data access.

After assessing my options, the service staff recommended I move my dad to a standalone plan so I have three lines (including my current mobile broadband plan) and can enjoy the multiline discount of 25 percent. My dad was on a previous plan no longer offered by my operator which allowed me to tag his plan to my own at just S$10 per month, which was an ideal plan for low-volume users like my dad.

I agreed, but said since I now have a mobile data access plan, I would terminate my mobile broadband plan--which costs S$12 after a 50 percent discount--when the contract ends next year and switch to the cheaper option of subscribing to an additional SIM card at S$10.70.

The service staff, however, said I would then end up with only two lines and would not be able to enjoy the 25 percent multiline discount. After adding up the sums, he said this would make having two lines and an additional SIM more expensive each month, compared to having three lines which would provide a 25 percent multiline discount and a recontracted mobile broadband plan which would provide a 50 percent discount.

It just didn't make sense to me. I highlighted how senseless it seemed to make me subscribe to a third line which I didn't need just to enjoy a bigger discount, when the operator could easily offer the same discount for the two lines I needed--minus the hassle of having to manage an unnecessary third line.

The service staff shrugged and said that's the way his company markets its services and encourages customer loyalty.

My operator isn't the only one offering these multiline discounts. All three mobile operators in Singapore--M1, SingTel and StarHub--offer discounts for multiple post-paid mobile lines, typically, 25 percent for three mobile lines and 30 percent for four.

Interestingly, at its earnings report earlier this week, SingTel Group CEO Chua Sock Koong said it recorded lower postpaid average revenue per user (ARPU) which dropped 8 percent to S$80 (US$64.25). This was partly dragged down by a higher take up of data-only SIM cards which, Chua noted, were less profitable.

The discussion with my operator's service staff got me thinking about subscriber numbers. According to local ICT regulator, Infocomm Development Authority of Singapore, the country's wireless broadband penetration rate in June 2012 was 160.2 percent and there were 7.8 million mobile subscriptions.

I'm now wonder, how many of these numbers are active lines and how many are inactive created just so subscribers like me can enjoy a bigger discount on their monthly plans?