I have a slight answer, although Im pretty sure they forward this to a company that will call for other reasons as well.
The other day I was trying to find a place to check my credit report, I had already gone to the annualcreditreport.com, but since thats once a year from the date you did it.... and so I was looking at trying to find places that I could do the free trial without having them try to charge the full amount to my card.
My friend was helping me search and found this one site and I went to it and it looked interesting like it would show me the credit report, etc., but after filling in the standard email address and phone (like you do), it sent me to a page that said, Thank you for your application, a representative will contact you shortly'.
I know this call is coming from that. I dont remember what the initial site's name was, but the page it took me to was creditattorney.com