I mean what is the momentary benefit from your side for registering using your referral code ? You did not plan anything like that or you missed while composing OP ? I ask this because this board is working that way. You cannot advertise something purely for third party benefits but you also should contribute from your side. I believe you will get some Euros for making people registering with them, right ?
Moreover, I doubt people here will not literally sell their documents for the need of 15EUR. Privacy is the big moto of this community. Do not expect to deviate from that for the sake of earning 15EUR.
Good one. Referral users will get +4EUR. PM me after you claim +15EUR to get extra 4EUR