Nagvert
A sneaky ad that jumps in your face because you installed some dumb software. It won’t stop bugging you until you pay it or punch it in the face.
Your anti-virus software keeps popping up with a 'Buy Premium' ad every 5 minutes.
You installed a free PDF reader and now it’s trying to sell you a $1000 subscription.
Your screen is covered in ads after you clicked 'Yes' to 10 pop-ups during install.