@dave
I sent my 500 local FB friends an invitation via Facebook instead of 500 emails or a group list. I added my link within the body of the text but there is an ATP graphic that automatically appears at the bottom of the message. Though I didn't check it yet, it must have the general link embedded within the graphic because I notice now that 3 or possibly more of my friends who commented on FB joined ATP. They must have joined via the graphic link because I received no notice that they joined. Others who used my link and joined, I did receive notification. So if people click on graphics, it might not have our individual links.
Also, when 'shared' on FB, only the graphic appears in the share, so it happens there as well.
It isn't as if I'm aching for more acorns, but others might be and I wanted you to know this is happening.