You might come across these annoying adds on amazon.com or craigslist that come in your way.
These says “Similar Products” and their url points to superfish.com adds. Here is how to disable or remove them.
How to remove Similar Products Ads or Superfish Ads
If you hover over the close button, it says “Close AwesomeScreen shot Plus side up”
To resolve this click Safari > Preferences. Then go to Extension tabs. Locate Awesome Screen Shot and uncheck “Enable Similar Product Search powered by Superfish”. Screen shot is below. You should be all set.
If you are having this issue in Google Chrome Browser, click here to resolve.