Why afflifiate link are blocked for some social media??

Why afflifiate link are blocked for some social media??

Hlw Seo Nation
Why afflifiate link are blocked for some social media?? like as Facebook google plus
etc
plz guyz any one can help??
i can't do promotion on my afflifiate links i'm trying a lot to bring some buyers from other side
i want to go level 4. but bad luck i'm unfortunetly i'm stuck in level 3
there is also some prblm my ip is banned from some forum that's why i can;t make a gd result.
i want social media promotion
plz help me
Best regards,
imran