I don't think there is any kind of spam. 0.25 SBD is just a cash incentive, I m offering for using referral. The project behind this is much much greater than my blog 😀.
I don't understand the point that how it's selling the number and email. It's simple signup and 0.25 SBD is smaller then what they are giving to the users for successful signup.

I need response from you sir because you have tipped me for my post on other topic earlier. If it makes sense that I am doing things wrong, I will edit and delete my post