Interesting, I thought just as much! Perhaps Simyo simply request this information to simply make it "more difficult" to obtain a sim because it's cheaper than even their own brand? Afterall, if you look around at the moment Base are really advertising hard for their own brand prepaid offer which I think is rather poor value in comparison to Simyo!
Simyo is great value but in Brussels every few weeks I find it impossible to make or receive calls at busy periods (4-5pm) so I guess the network is kind of stretched to the limits. Apart from that and the bad coverage down around Verviers/Spa I can't fault Simyo
I can't imagine why anybody would choose Base's own prepaid or one of the Mobistar/Proximus offers.
Now, a question...the data offer you have on contract with Base sounds interesting, especially now my Wind Mega-15000 only gives +/- 16MB for 30 Euro a month in Belgium. Is there any prepaid GPRS data offer in Belgium that can either beat Wind's price or the Virgin roaming price of EUR 7.50/MB?