Google seems to be put spamming and marketing in the same pot.
If I put a link on another site (like guest blogging or my Facebook posts), I'm usually doing it because I want people to click on that link and come to my site. I try to do those links according to Google rules.
Those sites are listed in Google Analytics as referring sites.
Based on what's happening to my pages, Google now seems to think that I'm being a spammer when I post those links.