Referral trackers are not automatic on any of the supplied social network buttons. The only way to include the referral tracker (at this time) is to manually enter the url link (with tracker) to the site.
This can be done by scrolling to the very bottom of the hub you want to submit and clicking, 'link to this page'
Choose your tracker from the drop down list and then cut and paste it.
Adding the url to pinterest:
For pinterest you would go to the pinterest website - click 'add' (top toolbar) - click, 'add pin' - paste the url with tracker - choose the photo that best describes your hub (it will provide you a slideshow of images from your hub) - add a description, select your board and submit.
I hope this helps :)