DM Notification for Nitro Ad?

I keep getting dm notifications for nitro ads that aren't actually worth anything, since I do not own, never use, and never plan to use nitro. It is completely worthless and a waste of my time. I keep checking to see who messaged or tagged me, and there's nothing there. Just a purple thing to click on so I can make it go away. 

I'm not surprised, just disappointed.