If you use Chrome or Safari, you can get "adblock," which takes out the ads from various webpages and replaces them with white space.
This version, called "catblock," takes out the ads and puts photos of cats there instead.
You can see some examples here:
The original version was released as an April Fools' Day joke, but the demand was such that the developer decided to make a stand-alone version, which costs $10/month.
It blocks not only pop-up ads and text ads but also those new video ads that come up before you're allowed to watch YouTube videos.
No dog version yet, but the developer owns a dog, so only a matter of time, I think!
[Edit to add: I have never used this (wrong browser type!) but have heard from a friend that Adblock is great, so I'm assuming Catblock will be equally great.]